16. Alerts and Action Sheets, Notifications, Application Lifecycle, and Persistence.srt

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[MUSIC]

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Stanford University,
斯坦福大学,

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>> Welcome to Stanford CS193P, Developing Applications for
> >欢迎来到斯坦福CS193P,开发应用程序

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iOS, Winter 2017,
iOS,2017年冬天,

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This is lecture number 16,
这是16号讲

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We have some miscellaneous topics today, all of which I
今天我们有一些各种各样的话题,所有的我

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think might be interesting to you for your final projects,
认为可能是有趣的,你的最后一个项目,

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We're gonna talk about alerts and
我们会谈论警报和

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alert's cousin: action sheet,
警报的表亲:动作表单,

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We'll talk about notifications,
我们将讨论通知,

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that's the radio station model from our MVC,
这是电台从我们的MVC模型,

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We'll talk about the application lifecycle: we
我们将讨论应用程序生命周期:我们

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already talked about the lifecycle of view,
已经讨论过的生命周期来看,

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but now we're gonna talk about the lifecycle of
但是现在我们要讨论的生命周期

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the whole application,
整个应用程序,

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And finally I'm gonna talk about persistence,
最后我要讲的持久性,

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How do we store stuff so
我们商店的东西怎么样

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that when our app launches it finds it and
当我们的应用程序启动它发现它

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of course you already know a couple ways of doing that,
当然,你已经知道的几个方法做,

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So I'm just gonna show you a couple others,
所以我要给你们几个,

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Let's start with this alerts and action sheets business,
让我们从这开始警报和行动表业务,

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These are "pop up and
这些都是“流行起来

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ask the user a question" kind of user interfaces,
要求用户一种问题”的用户界面,

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They're both just MVCs, alert and action sheet is just
他们都只是mvc,警报和动作表单是公正的

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an MVC, and they're always presented modally or in
MVC,他们总是模式地展示或

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a popover, which as we learned last time is basically modal,
弹窗,正如我们上次学基本上是模态的,

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So alerts pop up in the middle of the screen,
所以警报出现在屏幕的中间,

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they usually ask questions with only two answers,
他们通常只有两个答案,提问

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Like yes or no, OK and Cancel,
像“是”或“否”,可以取消,

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It is okay to have an alert I guess with just an OK button,
是好的一个警告我想只有一个OK按钮,

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Usually you wanna maybe think of if there's a better way to
通常你想也许想到如果有更好的方法

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present that information to the user than putting up
比将向用户显示信息

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And then we start talking about having three answers
然后我们开始讨论有三个答案

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an alert,
一个警告,

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in alert,
在警报,

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(A) you might wanna think about an action sheet,
(一)你可能想考虑一个动作表单,

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which I'll talk about in a second,
我将讨论在第二个,

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And (B) you just might wanna think about how am I getting
和(B)你可能想考虑我

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the user in the situation where I'm asking them
用户的情况,我问他们

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an emergency question,
一个紧急的问题,

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and there's three different answers or
和有三个不同的答案

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even more than three, that would really be interesting,
甚至超过三个,真的很有趣,

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So, alerts are quite disruptive to the UI,
所以,警报非常破坏UI,

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The user is happily using their user interface and
用户使用他们的用户界面和幸福

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then bam, the whole screen goes grey and there's this
然后bam,整个屏幕是灰色的

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little box in the middle and it's giving them some alert,
小盒子中间,给他们一些警告,

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I saw a class forum post about using alert, and there was
我看见一个类论坛帖子关于使用警报,有

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a great suggestion there from one of the TAs which is,
一个伟大的建议从一个助教的,

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this is something you wanna read the Apple human interface
这是你想要看苹果的人机界面

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guidelines about using alerts, when to use them,
指南使用警报、何时使用它们

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what to say in alert, things like that,
在警报,说点什么,

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And in fact, I recommend all of you read the human
事实上,我建议你读了所有的人

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interface guidelines from Apple in general, so
界面指南从苹果一般

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I'm gonna post that on the class forum, the link to that,
我要在类论坛帖子,链接,

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And I'm actually going to hold you to it in
和我要抱着你

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the UI part of the rubric in your final project,
UI的一部分标题在你最后的项目中,

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So pay some close attention to that, Apple's done
所以一些密切关注,苹果的完成

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a really good job of analyzing all the uses of the various UI
很好地分析所有的使用不同的UI

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elements and kind of what works well, what doesn't work
元素和类型的什么是有效的,什么是行不通的

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so well, and what's consistent between different things so,
很好,不同的东西之间的一致,

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An alert can ask the user for a little bit of text,
警报可以要求用户输入一些文本,

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This has been abused to
这是虐待

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make like login screens out of alerts and things like that,
做像登录屏幕警报之类的东西,

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It's pretty rare in my experience that you actually
它在我的经验,你真的很罕见

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wanna ask for text in an alert, but I'll show you in
对文本警报想问,但我将向您展示

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the demo today how to do it, but it's pretty unusual,
今天的演示怎么做,但它很不寻常,

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And then there's action sheets,
然后有行动表,

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now an action sheet does not gray out the whole screen and
现在动作表单没有灰色了整个屏幕

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appear in a little box,
出现在一个小盒子,

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instead on an iPhone it slides up from the bottom,
而不是在iPhone幻灯片从底部,

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And on an iPad, it's always gonna pop over,
在iPad上,它总是会流行,

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Now, an action sheet, I like to think of as
现在,动作表单,我喜欢的

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a branching decision user interface element,
一个分支决策用户界面元素,

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So a user has gotten to some point in the UI where you
所以用户已经在你的UI

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simply can't really proceed without knowing
无法真的不知道

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what the user wants to do,
用户想要做什么,

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So for an example: maybe you want to include an image in
所以对于一个例子:也许你想要包括一个图像

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something,
什么东西,

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A contact, and it's the profile image, or
一个联系人,这个概要文件的形象,或

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something like that,
类似的,

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And do you want that image to come from the camera,
和你想要图片来自相机,

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where it's gonna take a picture right now?
现在,它会拍照吗?

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Or from the photo library, past photos you've taken?
或从照片库、过去的照片你了?

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Or maybe from some collection view of clip art or something,
或者从某种集合视图的剪贴画,

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avatars or whatever that you provide, so you've kind of got
头像什么的,你提供,所以你得到的

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to go in one of these three directions so an active sheet
去其中的一个方向,所以一个活跃的表

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might slide up from the bottom and say you know add photo,
可能会从底部滑上来,说你知道添加照片,

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how do you wanna do it and you get these choices,
你想怎么做,你把这些选择,

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And usually there's Cancel also which is I didn't mean to
通常也有取消我不是故意的

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do that so cancel,
所以取消,

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Action usually have more then two answers,
行动通常有超过两个答案,

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It wouldn't be wrong necessarily to have an action
它不会是错的一定要有行动

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sheet with only two answers but
但表只有两个答案

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it just rarely does that circumstance arise,
只是很少出现这样的情况,

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So what do these two things look like?
这两个东西看起来像什么?

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This is what an action sheet looks like on an iPhone,
这是一个行动表看起来像在iPhone上,

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You see how it slides up from the bottom there and it has
你看到它如何从底部那里幻灯片,

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some choices in it and this is what an alert looks like,
一些选择,这是一个警告是什么样子,

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It takes over the whole screen,
它接管整个屏幕,

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This one happens to have a little text field in it,
这个恰好有一个文本字段,

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with two choices there,
有两个选择,

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So let's talk about the API,
所以让我们来谈谈API,

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To make these work because it's the exact same API,
做这些工作,因为它是相同的API,

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in fact it's the same MBC that does both of them,
事实上MBC是一样的,他们两人,

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This is the API to create this view controller,
这是API创建这个视图控制器,

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it's called a UI alert controller, and
它被称为一个UI警报控制器

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it just has a title, which is that thing at the top,
它有一个标题,在顶部,

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you see where it says redeploy Cassini,
你看到它重新部署卡西尼说,

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In the picture on the left there, that's the title,
在左边的图片,标题,

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And then message is just a short informational message
然后消息只是一个简短的信息消息

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telling you what the heck is going on right now,
告诉你现在到底是怎么回事,

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And then preferred style right there,
然后选择风格,

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if you set that to action sheet you get an action sheet,
如果你设置动作表单动作表单,

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If you set it to ,alert you're going to get an alert and
如果你把它,提醒你会得到一个警告

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I'll show you that,
我将向您展示,

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So the API for these is basically identical except for
所以对这些基本上是相同的除了API

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this one little preferred style thing right there,
这个小喜欢的风格的东西,

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So once you've created your alert, you wanna add buttons,
所以一旦你创建警报,你想添加按钮,

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Now adding buttons to your alert or action sheet,
现在将按钮添加到你的警报或动作表单,

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is done with add action,
完成添加操作,

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And the argument to add action is a UI alert action object,
和添加操作的参数是一个UI警报操作对象,

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And UIAlertAction is created with a title,
和创建UIAlertAction标题,

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So that's the title of the button,
这是按钮的标题,

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A style, and we'll talk about what all the styles,
风格,我们将讨论所有的风格,

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the button styles are,
按钮样式,

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And then a handler,
然后一个处理程序,

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Now, this handler is just a closure that you provide,
现在,这个处理程序只是提供一个闭包,

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This is the handler that's gonna get executed if that
这是处理程序的执行

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button is pressed, so that's the model for
按钮被按下,这样的模型

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alerts, it couldn't be simpler,
警报、不可能是简单的

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So let's look in example one, we got Orbit Saturn right
让我们看一个例子,我们得到了土星轨道

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there, see the title is Orbit Saturn,
看到标题是土星轨道,

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The style, this style is called ,default,
的风格,这种风格,默认情况下,

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So the default style, the text is gonna not be red, okay,
所以默认风格,文本会不会红,好吧,

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it's gonna be whatever color you've got going on in
它会发生的任何颜色你有

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your app there, usually blue,
你的应用,通常是蓝色的,

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And then in my closure here, this orbits Saturn, so
然后在我关闭这里,这个轨道土星,所以

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I'm gonna just go into orbit around Saturn,
我要进入环绕土星的轨道上,

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That's Cassini's mission by the way, to go to orbit around
这是卡西尼号的使命,去绕

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Saturn, so it's just going to do it, if I click that button,
土星,所以要这样做,如果我点击那个按钮,

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And let's add another button,
让我们添加一个按钮,

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this one's explore Titan, a moon out there,
这是探索泰坦,月亮,

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This is a little bit outside, well it's inside Cassini's
这一点外,在卡西尼号的

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mission but before we divert it,
任务在我们转移之前,

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we wanna make sure we're gonna log in for example,
我们要确保我们会登录为例,

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So here in my closure you see I've logged in,
所以在我关闭你看到我登录,

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made sure I'm logged in before I go to type,
让我我去之前登录类型,

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But it's the same kind of thing,
但这是同样的事情,

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a default button right there,
一个默认按钮,

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All right, so we've got those two default buttons,
好了,所以我们有这两个默认按钮,

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the blue ones,
蓝色的,

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How about that closeup of sun button,
特写镜头的阳光按钮,

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Now if Cassini closed up to the sun,
现在,如果卡西尼号关闭了太阳,

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it will be destroyed cuz it doesn't have enough
它将被破坏,因为它没有足够的

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propulsion to escape the sun gravity well there,
推进摆脱太阳引力井,

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So I made the style of this button be ,destructive,
所以我做了这个按钮的风格是破坏性的,

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instead of ,default,
相反的,默认情况下,

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And so ,destructive in an action sheet is gonna turn in
因此,表会在破坏性的行动

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turn up red okay just so that the user knows "
出现红色好这样用户知道”

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this one is probably something I should be carefully with",
这个可能是我应该仔细”,

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And anytime you have a destructive action in your
并在你任何时候你有一个破坏性的行动

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closure, you are probably going to want to confirm that
关闭,你可能会想确认

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this really want do to that destructive action,
这真的要做破坏性的行动,

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In this case, for example I'm gonna make them log in again
在这种情况下,例如我要让他们再次登录

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or something like that,
之类的,

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So that's destructive, and
这是破坏性的

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then finally we've got the cancel button at the bottom,
最后我们有取消按钮在底部,

168
00:07:42,962 --> 00:07:45,530
that's another type of button called Cancel style and
这是另一种类型的按钮叫风格和取消

169
00:07:45,599 --> 00:07:47,999
you can see that it looks a little different right,
你可以看到它看起来有点不同吧,

170
00:07:48,067 --> 00:07:50,435
it's kinda separated from the other buttons,
其他的纽扣有点分开,

171
00:07:50,503 --> 00:07:52,604
It's not destructive in fact it's the opposite of
这不是破坏性的实际上是相反的

172
00:07:52,672 --> 00:07:56,007
destructive, it gets you out of the problem,
破坏性的,它能让你的问题,

173
00:07:56,075 --> 00:07:56,974
Of this action sheet,
这个动作表单,

174
00:07:57,043 --> 00:07:58,609
to go back to wherever you were before,
回到无论你之前,

175
00:07:58,678 --> 00:08:01,079
you're not really gonna redeploy Cassini,
你不是真的要重新部署“卡西尼”号,

176
00:08:01,148 --> 00:08:03,014
And, but it is separated down there,
但它是分离,

177
00:08:03,083 --> 00:08:05,350
It kind of gives it just a little bit of a highlight,
它给它一点点的一大亮点,

178
00:08:08,655 --> 00:08:10,988
So I've added all my actions, I've got my buttons, and
我添加了我所有的行动,我有我的按钮,

179
00:08:11,057 --> 00:08:15,026
now I want to make this action sheet appear on screen,
现在我想让这个动作表单出现在屏幕上,

180
00:08:15,095 --> 00:08:17,495
And I do that with the normal method that
和我正常的方法

181
00:08:17,564 --> 00:08:20,031
we talked about before, which is present,
我们之前讲过,这是礼物,

182
00:08:20,099 --> 00:08:24,201
Remember, present is a view controller method that just
记住,现在只是一个视图控制器方法

183
00:08:24,270 --> 00:08:28,172
presents the new controller using whatever modal
提出了新的控制器使用任何模态

184
00:08:28,241 --> 00:08:30,808
presentation style is set in that view controller which by
演讲风格是由设置在视图控制器

185
00:08:30,877 --> 00:08:33,612
default is modal,
默认是模态的,

186
00:08:33,680 --> 00:08:37,915
So the action sheet slides at the bottom and
所以动作表单底部幻灯片

187
00:08:37,984 --> 00:08:41,386
it's being modally presented,
它是模式地展现,

188
00:08:43,657 --> 00:08:45,623
So that looks good on the iPhone but
这在iPhone上看起来不错,但

189
00:08:45,692 --> 00:08:47,058
what about on the iPad,
在iPad上呢,

190
00:08:47,127 --> 00:08:49,627
It would look terrible if that huge, if the thing was
它看起来可怕如果很大,如果是

191
00:08:49,696 --> 00:08:51,896
all the way the width of the iPad and came up,
所有的iPad和出来的宽度,

192
00:08:51,965 --> 00:08:54,498
Or if it was just tiny even in the middle it was just look
或者这只是小中间甚至只是看

193
00:08:54,567 --> 00:08:55,533
out of place right there,
不合适的,

194
00:08:55,601 --> 00:09:00,605
So of course on an iPad we put this action sheet in a pop
所以当然在iPad上我们把这个动作表单流行

195
00:09:00,674 --> 00:09:02,207
And whatever button causes us to have to do this branching
不管按钮使我们必须这样去做分支

196
00:09:02,208 --> 00:09:03,741
over,
结束了,

197
00:09:03,810 --> 00:09:06,677
decision, that's the button that we're gonna have
的决定,这是我们要的按钮

198
00:09:06,746 --> 00:09:08,213
the little arrow point to,
小箭头指向,

199
00:09:08,282 --> 00:09:10,782
So how do we make that work?
那么,我们如何让工作吗?

200
00:09:10,850 --> 00:09:12,650
we're presenting this alert using the modal style,
我们提出这个警报使用模态风格,

201
00:09:12,651 --> 00:09:14,451
Because right now,
因为现在,

202
00:09:14,521 --> 00:09:16,821
So it would come up modal on the iPad and
所以它会在iPad和模态

203
00:09:16,890 --> 00:09:17,555
it would look terrible,
它看起来很糟糕,

204
00:09:17,623 --> 00:09:19,857
So instead, we just have to go and
所以,我们必须去

205
00:09:19,926 --> 00:09:23,961
change our action sheet MVC here to have a modal
改变我们的动作表单MVC模式

206
00:09:24,030 --> 00:09:27,132
presentation style of pop over,
演讲风格的流行,

207
00:09:27,200 --> 00:09:29,900
That means it's gonna still present modal but pop over,
这意味着它会仍然存在模态但流行,

208
00:09:29,969 --> 00:09:31,802
Pop over is basically modal but
在基本上是模态但流行

209
00:09:31,871 --> 00:09:33,838
different kind of presentation style,
不同的演讲风格,

210
00:09:35,008 --> 00:09:36,941
And of course, when it pops up,
当然,当它出现时,

211
00:09:37,010 --> 00:09:39,911
we want the little arrow to point at the redeploy
我们希望小箭头指向重新部署

212
00:09:39,979 --> 00:09:42,147
button in my bar button item there,
按钮在工具栏按钮,

213
00:09:42,215 --> 00:09:44,716
And so we're gonna do that with that same pop over
所以我们要做的,同样的流行

214
00:09:44,784 --> 00:09:47,719
presentation controller that we set the delegate of last
表示控制器设置最后的代表

215
00:09:47,788 --> 00:09:49,921
time so we could control the adaptation,
时间我们可以控制的适应,

216
00:09:49,990 --> 00:09:52,056
Remember that from the demo?
记住,从演示?

217
00:09:52,125 --> 00:09:54,693
And so we're gonna use that same popover presentation
所以我们要使用同样的弹出窗口

218
00:09:54,761 --> 00:09:57,295
controller, and this time we're gonna set its bar
控制器,而这一次我们将设置它的酒吧

219
00:09:57,363 --> 00:09:59,798
button item to be the redeploy bar button item, and
按钮重新部署工具栏按钮,和

220
00:09:59,866 --> 00:10:02,900
the presentation popover presentation controller is
表示弹出窗口表示控制器

221
00:10:02,969 --> 00:10:05,737
smart enough to know "I'm gonna make my little arrow
足够聪明,知道“我要让我的小箭头

222
00:10:05,805 --> 00:10:07,071
point at that",
在项目”,

223
00:10:07,140 --> 00:10:09,507
And as I said before with the presentation controller,
就像我之前说的显示控制器,

224
00:10:09,576 --> 00:10:12,076
you could also have the little arrow point at an arbitrary
你也可以有小箭头指向任意

225
00:10:12,145 --> 00:10:14,379
rect in a view or at a button,
在视图或矩形按钮,

226
00:10:16,182 --> 00:10:17,915
That's it,
就是这样,

227
00:10:17,984 --> 00:10:20,885
Now, what happens if we put this code in there, this alert
现在,如果我们把这段代码,这个警报

228
00:10:20,954 --> 00:10:23,454
modes, modal presentation popover and we try and
模式,模式展示弹出窗口,我们试着

229
00:10:23,523 --> 00:10:25,824
run, (by the way it should be lower-case p popover there),
运行,(顺便说一下应该小写p弹窗),

230
00:10:25,892 --> 00:10:29,393
And we now try to run it back on the iPhone,
我们现在尝试运行在iPhone上,

231
00:10:29,462 --> 00:10:32,797
what's it gonna look like there?
它会是什么样子?

232
00:10:32,866 --> 00:10:35,300
It's gonna look exactly the same as it used to,
它会看起来一模一样,

233
00:10:35,368 --> 00:10:36,834
And why is that?
这是为什么呢?

234
00:10:36,903 --> 00:10:38,803
Adaptation, right?
适应,对吧?

235
00:10:38,872 --> 00:10:42,674
It's gonna adapt to the fact that in this case we have
它会适应这样的事实,在这种情况下

236
00:10:42,742 --> 00:10:45,543
a horizontally compact environment,
横向紧凑的环境中,

237
00:10:45,612 --> 00:10:47,445
And it's not going to put it in a popover,
这并不是要把它放在一个弹出窗口,

238
00:10:47,513 --> 00:10:49,346
So that's an automatic adaptation,
这是一个自动适应,

239
00:10:49,415 --> 00:10:50,681
same thing we had before,
同样的事情之前,

240
00:10:50,750 --> 00:10:52,216
So it'll look fine,
所以它会看起来很好,

241
00:10:52,285 --> 00:10:53,752
So if you have an app that's universal,
如果你有一个普遍的应用,

242
00:10:53,820 --> 00:10:56,654
you'll obviously put this little popover code
显然你会把这个弹窗代码

243
00:10:56,722 --> 00:11:00,058
in right there and it'll look fine on your other device,
在这里,它将在您的其他设备上看起来挺好,

244
00:11:00,127 --> 00:11:03,928
So that's the action sheet, what about alert?
这就是行动,警告呢?

245
00:11:03,996 --> 00:11:07,264
Same thing exactly, basically we're just gonna say that
完全相同,基本上我们要这样说

246
00:11:07,333 --> 00:11:10,034
the preferred style is alert in this case,
首选的风格是警报在这种情况下,

247
00:11:10,103 --> 00:11:13,504
Here I'm gonna add a cancel button there,
在这里我要添加一个取消按钮,

248
00:11:13,573 --> 00:11:18,976
I'm gonna add a login button,
我要添加一个登录按钮,

249
00:11:19,045 --> 00:11:22,546
And I'm also gonna add a text field to this one,
我也会添加一个文本框,

250
00:11:22,615 --> 00:11:24,082
so here's how I add a new text field,
这是我如何添加一个新的文本框,

251
00:11:24,150 --> 00:11:28,452
I just say to the MVC, the alert MVC, addTextField,
我只是说MVC,警报MVC,addTextField,

252
00:11:28,521 --> 00:11:31,022
Notice there's a little closure there that I can
注意这里有一个小,我可以关闭

253
00:11:31,091 --> 00:11:34,391
include to configure that text field,
包括文本字段的配置,

254
00:11:34,460 --> 00:11:36,093
Set the placeholder text,
设置占位符文本,

255
00:11:36,162 --> 00:11:39,029
Actually, this looks like a password, so I'll probably
实际上,这看起来像一个密码,所以我可能会

256
00:11:39,098 --> 00:11:41,866
want secure text turned on in there, things like that,
想要获得文本打开,类似这样的事情,

257
00:11:41,935 --> 00:11:45,336
Probably would wanna use trailing closure syntax there
可能想使用后关闭语法

258
00:11:45,405 --> 00:11:46,804
instead of using the whole thing, but
而不是使用整个事情,但是

259
00:11:46,873 --> 00:11:48,172
I just wanted you to see the argument,
我只是想让你看到的论点,

260
00:11:48,241 --> 00:11:49,674
it's called a configuration handler,
它被称为一个配置处理程序,

261
00:11:49,743 --> 00:11:50,341
cuz that's what it does,
因为这就是它的作用,

262
00:11:50,410 --> 00:11:51,743
It configures the text field,
它配置文本字段,

263
00:11:51,811 --> 00:11:54,578
You can add more than one text field if you want,
您可以添加多个文本框,如果你想要的,

264
00:11:54,647 --> 00:11:58,983
And then, the way you get the text out in your action,
然后,你得到的文本的方式在你的行动,

265
00:11:59,052 --> 00:12:02,119
this is sort of the login button's action right there,
这是登录按钮的动作,

266
00:12:02,188 --> 00:12:05,590
I'm gonna get the alert and ask for its text fields,
我要得到警报,要求它的文本字段,

267
00:12:05,658 --> 00:12:07,091
which is an array of text fields,
这是一个文本字段的数组,

268
00:12:07,159 --> 00:12:08,726
cuz I said you can have more than one text field,
因为我说你可以有不止一个文本字段,

269
00:12:08,795 --> 00:12:11,929
I'm gonna get the first one out of there,
我要去第一个出来,

270
00:12:11,998 --> 00:12:13,164
cuz I only have one,
因为我只有一个,

271
00:12:13,232 --> 00:12:15,566
I could do at sub-zero and sub-one, whatever,
我可以做在零度以下,了点,,

272
00:12:15,635 --> 00:12:17,035
depending on how many I have,
取决于有多少我,

273
00:12:17,103 --> 00:12:18,970
And, then I'm gonna get the text out of it,
然后,我要得到的文本,

274
00:12:21,040 --> 00:12:22,707
So now I have the text to other text, and so
所以现在我有文本与其他文本,所以

275
00:12:22,776 --> 00:12:23,475
it's really easy,
很简单,

276
00:12:25,411 --> 00:12:26,778
So let's have the TextField work,
我们有TextField工作,

277
00:12:28,147 --> 00:12:32,550
Again with alert style we just present it modally,
再次提醒风格模式地展示它,

278
00:12:32,619 --> 00:12:33,384
Now, in this case,
现在,在这种情况下,

279
00:12:33,453 --> 00:12:37,187
we don't present this in a popover on the iPad,
我们不提供这个弹窗在iPad上,

280
00:12:37,256 --> 00:12:40,090
So, it looks exactly the same as on the iPhone, a little box
所以,在iPhone上看起来一模一样,一个小盒子

281
00:12:40,159 --> 00:12:43,228
in the middle, which is okay, it actually looks okay there,
在中间,这是好的,它实际上看起来好了,

282
00:12:44,697 --> 00:12:47,331
So, nothing special in doing the alert case,
所以,做警告的情况下,没有什么特别的

283
00:12:47,400 --> 00:12:49,667
So that's it, that's alerts and action sheets,
就是这样,警报和行动表,

284
00:12:49,735 --> 00:12:51,102
I have a little demo,
我有一个小演示,

285
00:12:51,171 --> 00:12:52,102
FaceIt here,
FaceIt这里,

286
00:12:52,171 --> 00:12:53,404
Show you what this looks like,
告诉你这是什么样子,

287
00:12:54,574 --> 00:12:56,775
Code this up,
这个代码,

288
00:12:56,843 --> 00:12:58,876
Here we are in FaceIt, where we were before,
我们在FaceIt,我们之前,

289
00:12:58,945 --> 00:13:00,311
And watch what I'm gonna do here,
看我要做什么,

290
00:13:00,380 --> 00:13:04,715
So here I'm pressing my add button here to
所以这里我迫切的add按钮

291
00:13:04,784 --> 00:13:07,084
do this nice editor MVC,
这样做不错的编辑MVC,

292
00:13:07,153 --> 00:13:09,287
What happens here if I just hit done?
这里发生了什么如果我只是做了些什么?

293
00:13:10,423 --> 00:13:10,922
No,
不,

294
00:13:10,990 --> 00:13:11,990
It didn't work,
它不工作,

295
00:13:13,126 --> 00:13:14,025
That's weird,
这是奇怪的,

296
00:13:14,093 --> 00:13:14,692
I'll try again,
我会再试一次,

297
00:13:16,095 --> 00:13:17,395
Let's try something like grin,
让我们尝试类似的笑容,

298
00:13:17,463 --> 00:13:18,229
Squinting,
眯着眼,

299
00:13:18,298 --> 00:13:18,863
Done,
完成了,

300
00:13:20,399 --> 00:13:21,699
I just made this work,
我只是做了这个工作,

301
00:13:21,768 --> 00:13:22,733
What's going on, Well, actually,
发生了什么,实际上,

302
00:13:22,802 --> 00:13:26,871
this did work because look, it added one right here,
这个工作,因为看起来,它增加了一个,

303
00:13:26,940 --> 00:13:28,873
It's just the name was blank,
的名字是空白的,

304
00:13:30,443 --> 00:13:33,511
I went up here, I hit done and I didn't put a name,
我去,我完成了,我没有把一个名字,

305
00:13:33,580 --> 00:13:36,213
So it comes back, this is really bad UI,
所以它回来,这是非常糟糕的UI,

306
00:13:36,282 --> 00:13:38,182
because it "worked",
因为它“工作”,

307
00:13:38,251 --> 00:13:40,818
But this is clear now what the user intends, for there to be
但这是清楚现在用户意图,有

308
00:13:40,887 --> 00:13:42,954
blank lines there they can't even tell the difference
空行,他们甚至不能区分

309
00:13:43,022 --> 00:13:44,889
between when there's something there or not,
之间有或没有时,

310
00:13:44,958 --> 00:13:47,791
So really what we'd like is, when we click done right here,
所以我们希望的是,当我们点击完成,

311
00:13:47,860 --> 00:13:50,327
we would like to put up an alert if you
我们想提出一个警告,如果你

312
00:13:50,396 --> 00:13:52,197
didn't give a name,
没有给一个名字,

313
00:13:52,265 --> 00:13:53,831
And maybe we'll even put a text field in and
也许我们甚至会把一个文本字段

314
00:13:53,900 --> 00:13:55,433
let you type the name right there in the alert,
让你输入名字在警报,

315
00:13:55,501 --> 00:13:58,602
Which is a little questionable UI but it's good for demo,
这是一个小问题UI但是演示,很好

316
00:13:58,671 --> 00:13:59,470
So that's what we're gonna do,
这就是我们要做的,

317
00:13:59,539 --> 00:14:02,273
So we're gonna have this done button right here,
所以我们要有这个完成按钮,

318
00:14:02,342 --> 00:14:05,677
put up an alert if the name field is empty,
提出一个警告如果name字段为空,

319
00:14:07,079 --> 00:14:07,845
So how do we do that?
那么我们该如何做呢?

320
00:14:07,913 --> 00:14:12,583
Let's go over here to our editor MVC, the code here for
让我们去这里编辑MVC,代码在这里

321
00:14:12,652 --> 00:14:13,284
our editor,
我们的编辑器,

322
00:14:13,353 --> 00:14:15,152
Remember this code right here,
记住这里的代码,

323
00:14:15,221 --> 00:14:16,621
Pretty simple,
很简单,

324
00:14:16,689 --> 00:14:21,725
And what I'm gonna do, I wanna prevent that unwind segue,
我要做什么,我想阻止unwind,

325
00:14:21,794 --> 00:14:24,295
that done unwind segue, I wanna prevent it from
unwind完成,我想阻止它

326
00:14:24,364 --> 00:14:27,164
happening if the name is empty,
如果名称是空的,发生

327
00:14:27,233 --> 00:14:28,933
So how do I prevent a segue?
那么我怎么阻止segue呢?

328
00:14:30,303 --> 00:14:32,203
What's the method that I add?
我添加的方法是什么?

329
00:14:34,140 --> 00:14:36,707
I hear whispers of it, yes I think I hear it,
我听到窃窃私语,是的,我想我听到它,

330
00:14:36,776 --> 00:14:39,476
Should perform segue, remember that one,
应该执行segue,记住一个,

331
00:14:39,545 --> 00:14:43,514
should perform segue so should perform segue with identifier,
应该执行segue应该执行segue标识符,

332
00:14:43,583 --> 00:14:45,182
I'm gonna implement that,
我要实现,

333
00:14:45,251 --> 00:14:49,621
And I'm just gonna say if the identifier is my unwind,
我只是想说如果标识符是我放松,

334
00:14:49,689 --> 00:14:52,323
Does anyone remember what our identifier was?
有谁还记得我们的标识符是什么吗?

335
00:14:52,391 --> 00:14:53,357
Let's go look it up so
我们去查一下

336
00:14:53,426 --> 00:14:55,726
we can remind ourselves how we find it,
我们可以提醒我们如何找到它,

337
00:14:55,795 --> 00:14:58,662
So, the it was, the unwind out of here,
所以,放松的,

338
00:14:58,731 --> 00:15:01,899
Now, of course, we don't get to see our unwind segues
现在,当然,我们看不到unwind segue

339
00:15:01,968 --> 00:15:03,901
as these little arrow lines,
这些小箭头线,

340
00:15:03,970 --> 00:15:07,071
We had to go look in our document outline over here,
我们必须去看文档大纲,

341
00:15:07,139 --> 00:15:10,741
And click on this MVC and look at the bottom right there,
点击这个MVC和看底部,

342
00:15:10,810 --> 00:15:15,079
unwind segment, segue add Emotion, we called it,
放松,继续增加情感,我们叫它,

343
00:15:15,148 --> 00:15:17,114
When we click on inspector, we'll see it, and
当我们点击检查器,我们会看到它,

344
00:15:17,183 --> 00:15:21,719
we call it Add Emotion, that's the identifier for that segue,
我们叫它添加情感,segue的标识符,

345
00:15:21,788 --> 00:15:23,987
So now we know what our segue's called,
所以现在我们知道segue叫做,

346
00:15:24,056 --> 00:15:24,755
let's check it here,
让我们检查它,

347
00:15:24,824 --> 00:15:28,726
So if the identifier is Add Emotion, and
如果标识符是添加情感和

348
00:15:28,795 --> 00:15:34,131
if our name isEmpty, then we wanna return false,
如果我们的名字isEmpty,那么我们想返回false,

349
00:15:34,200 --> 00:15:37,302
We do not want to allow to segue to happen if that's
我们不想让segue如果发生

350
00:15:37,370 --> 00:15:40,337
empty, otherwise, what are we gonna return?
空的,否则,我们会返回什么呢?

351
00:15:40,406 --> 00:15:44,275
Well, some people would mistakenly say return true,
嗯,有些人错误地认为返回true,

352
00:15:44,344 --> 00:15:46,043
But you don't want to return true there,
但是你不想还真有,

353
00:15:46,112 --> 00:15:50,915
you want to return super should perform segue,
你想返回超级应该执行segue,

354
00:15:50,984 --> 00:15:53,584
Because you wanna give your super class a chance to,
因为你想给你的超类的机会,

355
00:15:53,653 --> 00:15:57,020
it might have some segues, and you wanna give it a chance,
它可能有一些而已,你想给它一个机会,

356
00:15:57,089 --> 00:16:00,591
To see if it want to allow this particular identifier,
是否想让这个特定的标识符,

357
00:16:00,659 --> 00:16:03,294
So don't forget that, when you're overriding these things
所以别忘了,当你压倒一切的这些事情

358
00:16:03,363 --> 00:16:06,863
don't return true there give your super class chance,
还真没有给你超类的机会,

359
00:16:06,932 --> 00:16:10,501
So let's run this just to see what this did, we haven't done
让我们运行这个只是为了看看这个,我们还没有完成

360
00:16:10,569 --> 00:16:14,137
any alert here obviously we're just preventing that done,
任何警告显然我们只是做预防,

361
00:16:14,206 --> 00:16:17,441
Let's see even that works there we go,
让我们看看甚至工作好了,

362
00:16:17,509 --> 00:16:21,679
Add, I'm not putting a name in here, done and turn off,
添加,我不会给一个名字在这里,完成关闭,

363
00:16:21,747 --> 00:16:25,750
It didn't unwind, see but this would also be terrible UI,
它没有放松,看到这个UI也将是多么可怕,但

364
00:16:25,819 --> 00:16:28,886
The user would think no, delete this app,
用户会认为没有,删除这个应用,

365
00:16:28,954 --> 00:16:30,287
it doesn't work,
它不工作,

366
00:16:30,356 --> 00:16:33,324
This is a broken app, I'm clicking this button here,
这是一个破碎的应用,我点击这个按钮,

367
00:16:33,392 --> 00:16:35,292
It's not doing anything, forget it,
不做任何事,忘记它,

368
00:16:35,361 --> 00:16:37,395
So you never wanna have a UI like that where you press
所以你永远不会想要有这样一个UI的新闻

369
00:16:37,463 --> 00:16:39,129
a button and it just does nothing,
一个按钮,它就什么也不做,

370
00:16:39,198 --> 00:16:43,901
that's really bad UI so do never do that,
这是非常糟糕的UI做从来没有这样做,

371
00:16:43,970 --> 00:16:47,604
Instead we want to do an alert, so I'm gonna create
相反,我们要做一个警告,所以我要创造

372
00:16:47,673 --> 00:16:51,141
a little function to put all this alert stuff in,
一个小函数把这些警报的东西,

373
00:16:51,210 --> 00:16:54,979
private funk we'll call it handle unnamed face,
私人恐慌我们叫它处理未具名的脸,

374
00:16:55,047 --> 00:16:56,947
And in there we'll do our alert business so
在那里我们会做业务,所以我们的警觉

375
00:16:57,016 --> 00:16:58,316
I'm just gonna do it up here,
我要这样做,

376
00:16:58,384 --> 00:17:00,051
I'm gonna handle this UnnamedFace,
我要处理这种UnnamedFace,

377
00:17:00,119 --> 00:17:03,387
When I'm still gonna prevent this segway because I cannot
当我仍然要防止这个赛格威,因为我不能

378
00:17:03,456 --> 00:17:05,656
do the segway when this name's empty,
赛格威这个名字是空的,什么时候

379
00:17:05,725 --> 00:17:07,358
So I'm still gonna return false but I'm
所以我仍然要返回错误但我

380
00:17:07,426 --> 00:17:09,727
gonna handle this UnnamedFace along the way here,
要处理这一路上UnnamedFace,

381
00:17:10,863 --> 00:17:12,430
So here's handle unnamed face,
这是处理未具名的脸,

382
00:17:12,499 --> 00:17:17,935
I want an alert easy alert = UIAlertController,
我想要一个警告容易警报= UIAlertController,

383
00:17:18,004 --> 00:17:21,105
Here's the argumnet down here, title,
这是argumnet下面、标题

384
00:17:21,174 --> 00:17:24,375
Let's have the title be something like Invalid Face
让我们标题是无效的

385
00:17:24,443 --> 00:17:26,777
and the message, there's a lot of good stuff in the human
消息,有很多好东西的人

386
00:17:26,846 --> 00:17:28,813
interface guidelines about message here,
接口指南关于消息,

387
00:17:28,881 --> 00:17:31,616
You don't want to scold your user with these alert
你不想骂你的用户与这些警报

388
00:17:31,684 --> 00:17:32,683
messages,
消息,

389
00:17:32,751 --> 00:17:34,718
We want to be nice to them, so we just want
我们要善待他们,所以我们想要的

390
00:17:34,787 --> 00:17:37,154
to kind of explain nicely what's going on like,
的很好地解释发生了什么,

391
00:17:37,223 --> 00:17:39,556
We'll just have a face must have a name or
我们必须有一个名称或只有一个脸

392
00:17:39,625 --> 00:17:42,993
something like that, maybe even that's a little harsh,
类似的,甚至有点苛刻,

393
00:17:43,062 --> 00:17:46,129
But, we'll say, we don't want it to be too long but by
但是,我们会说,我们不希望它太长但

394
00:17:46,198 --> 00:17:49,634
the same token we don't it to be, you know, terse and mean,
同样我们不,你知道,简洁,意思是,

395
00:17:49,702 --> 00:17:51,635
So we're kind of somewhere in the middle, so
所以我们中间,所以

396
00:17:51,704 --> 00:17:53,203
we'll say "a face must have a name",
我们会说“必须有一个名称“

397
00:17:53,272 --> 00:17:54,938
And of course the style here, what is it?
当然这里的风格,它是什么?

398
00:17:55,007 --> 00:17:56,674
Is it action sheet?
动作表单吗?

399
00:17:56,743 --> 00:18:01,912
No, it's Alert style, so I've created an alert,
不,这是警告风格,所以我创建了一个警告,

400
00:18:01,980 --> 00:18:05,349
This is a view controller this is returning, if I look at
这是一个视图控制器返回,如果我看

401
00:18:05,417 --> 00:18:08,853
the type of alert right here, it's an alert controller,
类型的警报,警报控制器,

402
00:18:08,922 --> 00:18:12,022
which is a UI view controller sub class,
这是一个用户界面视图控制器子类,

403
00:18:12,091 --> 00:18:13,924
So I've got this nice thing,
所以我有这个好处,

404
00:18:13,993 --> 00:18:16,093
let's just actually present this and see what happens,
实际上我们现在这个,看看会发生什么,

405
00:18:16,162 --> 00:18:21,732
Let's go present Alert Animated,
让我们去提醒动画,

406
00:18:21,800 --> 00:18:25,069
True, and we don't even need a completion handler,
真的,我们甚至不需要完成处理器,

407
00:18:25,137 --> 00:18:27,571
we rarely need that completion handler by the way,
我们很少需要完成处理器,

408
00:18:27,640 --> 00:18:30,808
You know, it just tells you, I've finished presenting this
你知道,它只是告诉你,我已经完成了这个

409
00:18:30,877 --> 00:18:33,211
thing, if you want to do something you could,
的事情,如果你想做一些你可以,

410
00:18:36,382 --> 00:18:37,315
Let's go back here,
让我们回到这里,

411
00:18:37,383 --> 00:18:40,451
Go here, again, I'm not putting the name in, done,
到这里,再一次,我不会给这个名字,,

412
00:18:40,520 --> 00:18:41,819
Well it's better,
这是更好,

413
00:18:41,888 --> 00:18:43,387
My app is still completely broken though,
我的应用程序仍然是完全坏了,

414
00:18:43,455 --> 00:18:46,924
because whoa, I got this modal view controller up,
因为哇,我得到这个模态视图控制器,

415
00:18:46,993 --> 00:18:48,725
and there's no way to get rid of it,
没有办法摆脱它,

416
00:18:48,794 --> 00:18:49,893
So my app is completely dead,
我的应用程序是完全死了,

417
00:18:49,962 --> 00:18:51,261
The only way to get out of this,
唯一的办法,

418
00:18:51,330 --> 00:18:53,097
is to literally kill the app,
是真的杀了这个应用程序,

419
00:18:53,165 --> 00:18:53,798
So we don't want that,
所以我们不希望这样,

420
00:18:53,866 --> 00:18:57,801
We never wanna have an alert with no buttons, obviously,
我们从来没有想有一个警告,没有按钮,显然,

421
00:18:57,870 --> 00:19:00,471
So let's could give it a button, go over here,
让我们给它一个按钮,可以在这里,

422
00:19:00,540 --> 00:19:04,775
To our alert, say alert,addAction remember is
警报,警告说,addAction记住

423
00:19:04,844 --> 00:19:09,113
how we do that, and it's got a UIAlertAction and
我们如何做到这一点,和它有一个UIAlertAction吗

424
00:19:09,181 --> 00:19:12,049
let's look at the arguments here for AlertAction,
让我们看看AlertAction的论点,

425
00:19:12,118 --> 00:19:15,585
We got a title, so, I'm just gonna put an OK button,
我们有一个标题,所以,我要把一个OK按钮,

426
00:19:15,654 --> 00:19:17,555
I just got finished telling you that you really don't
我刚刚结束了告诉你,你真的不要

427
00:19:17,624 --> 00:19:19,123
wanna have alerts that'd only have one button,
想提醒,就只有一个按钮,

428
00:19:19,191 --> 00:19:20,257
But this is a demo, so
但这是一个演示,所以

429
00:19:20,326 --> 00:19:21,925
I'm just showing you how to add a button,
我只是向您展示如何添加一个按钮,

430
00:19:21,994 --> 00:19:23,160
Here's an OK button,
这里有一个OK按钮,

431
00:19:23,229 --> 00:19:24,595
The style on this one is a default,
这是一个默认的风格,

432
00:19:24,664 --> 00:19:26,763
it's just a default button, it's not destructive, or
它只是一个默认按钮,这不是破坏性的,或

433
00:19:26,832 --> 00:19:27,865
anything like that,
类似的,

434
00:19:27,934 --> 00:19:31,001
One could argue this should almost be a cancel,
可能有人会说这几乎应该取消,

435
00:19:31,070 --> 00:19:33,437
You're gonna see that I'm not gonna make it like a cancel
你会看到,我不会让它像一个取消

436
00:19:33,505 --> 00:19:37,641
appear in a second and then the handler, we're not
出现在第二个,然后处理程序,我们没有

437
00:19:37,710 --> 00:19:40,044
doing anything when we click OK, so now let's run it again,
做任何事情当我们单击OK,现在让我们再次运行它,

438
00:19:41,514 --> 00:19:43,247
Oops, got a parenthesis there,
哦,有一个括号,

439
00:19:43,316 --> 00:19:44,982
All right, let's run again,
好吧,让我们再次运行,

440
00:19:47,352 --> 00:19:48,919
So here we go, we add,
所以我们开始吧,我们添加,

441
00:19:48,988 --> 00:19:52,289
not putting a name, hit done, comes up invalid face,
不要把一个名字,点击完成,出现无效的脸,

442
00:19:52,358 --> 00:19:56,026
A face must have a name, now I'm back here,
必须有一个名称,现在我回到这里,

443
00:19:56,095 --> 00:19:59,629
This probably is minimally okay, right?
这可能是最低限度,对吧?

444
00:19:59,698 --> 00:20:03,601
This is probably fine, the user would immediately know,
这可能是好,用户会立即知道,

445
00:20:03,670 --> 00:20:05,836
I gotta give it a name and they go up here and
我要给它一个名字,他们在这里

446
00:20:05,905 --> 00:20:07,772
give it a name and all would be well,
给它一个名字,一切就都好了,

447
00:20:07,840 --> 00:20:10,841
But in order to show you text fields in alert, how about
但是为了显示你在警告文本字段,怎么样

448
00:20:10,909 --> 00:20:13,577
when this comes up If give give them a text field,
当出现如果给给他们一个文本字段,

449
00:20:13,646 --> 00:20:16,380
And let them enter a name, so they don't have to go back,
和让他们输入一个名字,所以他们没有回去,

450
00:20:16,449 --> 00:20:18,281
enter a name, and click Done,
输入一个名称,然后单击完成,

451
00:20:18,350 --> 00:20:20,885
They can just type the name right here, and click OK,
他们可以输入名称,并单击OK,

452
00:20:20,953 --> 00:20:23,987
So how do we do that, well one thing in our alert,
所以我们如何做到这一点,有一件事在我们的警惕,

453
00:20:24,056 --> 00:20:26,524
is that we would want to add a text field,
是我们想要添加一个文本框,

454
00:20:27,860 --> 00:20:30,060
And in configuration handler we could figure this
我们可以算这和配置处理程序

455
00:20:30,129 --> 00:20:30,928
to do whatever we want,
做我们想做的事,

456
00:20:30,997 --> 00:20:35,032
we'll just say we won't have a configuration handler here,
我们就说我们不会有一个配置处理程序,

457
00:20:35,101 --> 00:20:40,671
And then in our add action, when the user click OK,
然后我们加上行动,当用户单击OK时,

458
00:20:40,739 --> 00:20:44,608
I'm gonna look in that text field,
我要看,文本字段,

459
00:20:44,676 --> 00:20:50,213
get the text out of it and put it in my name field,
从中获得的文本,把它放进我的名字,

460
00:20:50,282 --> 00:20:53,150
Remember that this handler gives you the action itself,
记住,这个处理程序给你行动本身,

461
00:20:53,218 --> 00:20:54,518
the same alert action,
相同的预警行动,

462
00:20:54,586 --> 00:20:56,954
It's kind of like if you had a delegate method, you'd get
这就像如果你有委托方法,你会得到

463
00:20:57,023 --> 00:20:59,190
the thing that's delegating same kind of thing here,
授权的同样的事情,

464
00:20:59,258 --> 00:21:01,792
This action here would be passed to you in the handler,
这个行动将传递给你的处理程序,

465
00:21:01,861 --> 00:21:03,160
we don't need it though,
不过,我们不需要它

466
00:21:03,228 --> 00:21:07,898
I'm just going to say that my self,name/text field,
我只想说我的自我,名称/文本框,

467
00:21:10,035 --> 00:21:14,738
Its text equals the alerts
它的文本=警报

468
00:21:14,807 --> 00:21:19,910
text fields, text fields,
文本字段、文本字段

469
00:21:19,979 --> 00:21:25,782
text, actually I guess that's
文本,我猜的

470
00:21:25,851 --> 00:21:30,454
all I needed to do there,
所有我需要做的,

471
00:21:34,860 --> 00:21:36,460
Text field is an array,
文本框是一个数组,

472
00:21:36,529 --> 00:21:39,797
So let's grab the first one out of there and get its text,
让我们抓住第一个出来,得到它的文本,

473
00:21:39,866 --> 00:21:43,266
So this is fine except for look we're presenting this
这是好的除了我们展示这个样子

474
00:21:43,335 --> 00:21:46,570
thing before we add the text field so that's not good,
之前我们添加文本框,这样不好,

475
00:21:46,639 --> 00:21:50,140
So let's put this down here and try again,
让我们把这个,再试一次,

476
00:21:50,209 --> 00:21:53,243
All right, go here, we're done,
好了,到这里,我们做的,

477
00:21:53,312 --> 00:21:55,246
Now I have a text field in here,
现在我有一个文本字段,

478
00:21:55,314 --> 00:21:58,715
we'll say Foo is the name we want, and we click Okay and
我们会说Foo是我们想要的名字,然后点击好

479
00:21:58,784 --> 00:22:01,619
it puts Foo in their name text field, excellent,
它把Foo名称文本框,非常好,

480
00:22:01,687 --> 00:22:04,121
However we're still making them go back and
然而我们仍然让他们回去

481
00:22:04,190 --> 00:22:05,489
click done again, right?
再次点击完成,对吗?

482
00:22:05,558 --> 00:22:09,260
Because now I can hit done and it works, got this in here,
因为现在我可以做的工作,这在这里,

483
00:22:09,328 --> 00:22:11,295
But it would be really nice if I go into this
但它将会很好如果我进入这个

484
00:22:11,363 --> 00:22:13,396
unnamed situation, and I typed something here, and
不愿透露姓名的情况下,我输入一些东西,

485
00:22:13,465 --> 00:22:16,700
I click okay, if it would just do done automatically,
我点好,如果它会自动完成,

486
00:22:16,769 --> 00:22:20,470
So does anyone remember how we perform a segue from code?
谁还记得我们从代码执行segue吗?

487
00:22:20,539 --> 00:22:21,271
Cuz that's what we need to do,
因为这是我们需要做的,

488
00:22:21,340 --> 00:22:24,008
we need to perform that unwind from our code,
我们从我们的代码需要执行,放松,

489
00:22:26,579 --> 00:22:29,046
I'm gonna do it right here in my action handler,
在这里我要做在我的操作处理程序,

490
00:22:29,115 --> 00:22:32,949
I'm just gonna say self,performSegue,
我只是想说自我,performSegue,

491
00:22:33,018 --> 00:22:36,720
Exactly what you would think and the identifier?
你想和标识符?

492
00:22:36,788 --> 00:22:38,221
It's that add emotion,
那就是增加情感,

493
00:22:38,290 --> 00:22:40,890
which is the unwind segue and the sender,
unwind和发送者,

494
00:22:40,959 --> 00:22:42,092
I don't really care who the sender is,
我不在乎谁是发送者,

495
00:22:42,161 --> 00:22:43,326
I don't look at that in my prepare,
我不要看,我准备,

496
00:22:43,395 --> 00:22:45,029
I don't need it for any reason,
我不需要任何理由,

497
00:22:47,065 --> 00:22:48,366
That's all that's required there,
这是所有必需的,

498
00:22:50,402 --> 00:22:51,001
It's a good chance for
这是一个很好的机会

499
00:22:51,069 --> 00:22:53,771
me to show you perform segue, segueing from code,
我给你执行segue segue从代码中,

500
00:22:57,843 --> 00:22:59,409
All done, here we go here,
全部完成,我们开始在这里,

501
00:22:59,478 --> 00:23:02,546
Let's do our favorite one which is contentment right
让我们做我们最喜欢的一种满足感是正确的

502
00:23:02,615 --> 00:23:04,948
there, so I didn't put the name in here,
在那里,所以我没有把名字放在这里,

503
00:23:05,017 --> 00:23:08,952
Done, face must have a name, I'll say content,
做,必须有一个名称,我要说的内容,

504
00:23:09,021 --> 00:23:11,521
We click Okay, it comes back,
我们点好了,回来,

505
00:23:11,590 --> 00:23:16,226
Here it is, everybody understand "alert"?
在这里,每个人都理解“警戒”?

506
00:23:16,295 --> 00:23:19,663
Alert's pretty straightforward to implement, action sheet is
警报实现很简单,动作表单

507
00:23:19,732 --> 00:23:22,099
pretty much exactly the same way, no text fields,
几乎完全相同的方式,没有文本字段,

508
00:23:22,167 --> 00:23:24,935
Obviously, in an action sheet, but
显然,在一个动作表单,但是

509
00:23:25,004 --> 00:23:27,971
you just add more actions in that case,
在这种情况下,你只需要添加更多的行动

510
00:23:28,040 --> 00:23:31,008
All right, back to our slides,
好了,回到我们的幻灯片,

511
00:23:35,114 --> 00:23:40,317
The next thing we're gonna talk about Is notifications,
接下来我们要讨论的是通知,

512
00:23:40,386 --> 00:23:43,554
Notifications are the radio station in that MVC
通知是MVC的电台

513
00:23:43,622 --> 00:23:47,091
talk I gave right at the beginning of the quarter,
说我给在本季度的开始,

514
00:23:49,228 --> 00:23:50,527
This is how we can, essentially,
这是我们如何,从本质上讲,

515
00:23:50,596 --> 00:23:55,332
broadcast information blindly to other objects in our
广播信息盲目地在我们的其他对象

516
00:23:55,400 --> 00:23:58,602
application and have them tune in if they're interested,
应用程序,让他们收听,如果他们感兴趣,

517
00:23:58,670 --> 00:24:00,905
So how do we do this?
那么我们如何做呢?

518
00:24:00,973 --> 00:24:03,473
The key to making notifications work is this
通知这是工作的关键

519
00:24:03,542 --> 00:24:06,576
class called NotificationCenter,
类称为NotificationCenter,

520
00:24:06,645 --> 00:24:10,080
So there is a default NotificationCenter,
这是一个默认的NotificationCenter,

521
00:24:10,148 --> 00:24:14,485
which you get by accessing the static bar called default
你得到通过访问静态栏默认

522
00:24:14,553 --> 00:24:15,985
on NotificationCenter,
NotificationCenter,

523
00:24:16,054 --> 00:24:17,521
So you have NotificationCenter,default
NotificationCenter,违约

524
00:24:17,590 --> 00:24:20,257
gives you this default notification center,
给你这个默认的通知中心,

525
00:24:20,326 --> 00:24:23,126
And so you can do two things once you have a default
所以你可以做两件事一旦违约

526
00:24:23,195 --> 00:24:24,160
notification center?
通知中心吗?

527
00:24:24,229 --> 00:24:27,331
You can sign up to listen to radio broadcast or
你可以听广播或迹象

528
00:24:27,400 --> 00:24:29,099
you can broadcast,
你可以播放,

529
00:24:29,167 --> 00:24:30,600
Now who that you things you can do,
现在,你可以做的事情,

530
00:24:30,669 --> 00:24:35,539
super simple API really they do nice job with this one,
超级简单的API真的与这个,他们做的不错

531
00:24:35,608 --> 00:24:39,143
So first let's talk about how you sign up to listen,
首先让我们来谈谈如何签署听,

532
00:24:39,211 --> 00:24:41,344
you wanna listen to a certain radio station,
你想听一个电台,

533
00:24:41,413 --> 00:24:43,947
It's done with this method that you send to the default
用这种方法,你发送到默认

534
00:24:44,016 --> 00:24:46,717
notification center called add observer,
通知中心添加观察,

535
00:24:46,785 --> 00:24:47,984
So add observer means
所以添加观察者意味着

536
00:24:48,053 --> 00:24:50,020
I'm listening to this radio station,
我在听这个电台,

537
00:24:50,089 --> 00:24:52,288
And has three arguments, the first one for
有三个参数,第一个

538
00:24:52,357 --> 00:24:55,926
name is the name of the radio station,
名字是电台的名称,

539
00:24:55,994 --> 00:24:58,161
Now the type of that is NSNotification,name,
现在NSNotification的类型,名称,

540
00:24:58,230 --> 00:24:59,963
And I'm gonna talk about that in a second, but
我将谈论这个,但是

541
00:25:00,032 --> 00:25:02,833
that's just the name of radio station you what to listen to,
这是电台的名字你听什么,

542
00:25:02,902 --> 00:25:05,368
The second argument is object: Any?
第二个参数是对象:吗?

543
00:25:05,437 --> 00:25:11,909
That's basically, in a sense, the sender, the broadcaster,
基本上,在某种意义上,发件人,广播,

544
00:25:11,977 --> 00:25:12,876
If you're only listen,
如果你只倾听,

545
00:25:12,945 --> 00:25:15,279
interested in a radio station that's broadcast from
感兴趣的电台广播

546
00:25:15,347 --> 00:25:17,881
a certain object, then you can put something there,
一个特定的对象,然后你可以把东西放在那里,

547
00:25:17,950 --> 00:25:20,850
If you put nil there, it means anybody broadcasting on that
如果你把零,这意味着任何广播

548
00:25:20,919 --> 00:25:22,419
radio station, I'm interested,
广播电台,我感兴趣,

549
00:25:23,823 --> 00:25:25,055
So it's just a way of narrowing down,
所以它只是缩小的一种方式,

550
00:25:25,124 --> 00:25:27,624
The radio stations are kind of weird in that you can have
奇怪的广播电台都是你

551
00:25:27,693 --> 00:25:30,660
multiple people broadcasting on the same station,
多人广播在同一车站,

552
00:25:30,729 --> 00:25:33,997
It's not like a real radio station where it's only one
它不像一个真正的广播电台的只有一个

553
00:25:34,066 --> 00:25:35,632
radio station,
广播电台,

554
00:25:35,701 --> 00:25:37,267
And then a third argument is a queue,
然后第三个参数是一个队列,

555
00:25:37,336 --> 00:25:39,603
(it's actually four arguments, I guess),
(实际上是四个参数,我猜),

556
00:25:39,672 --> 00:25:42,439
The third argument is a queue that you're gonna run
第三个参数是你要运行一个队列

557
00:25:42,507 --> 00:25:43,407
this closure on,
这个闭包,

558
00:25:43,475 --> 00:25:45,442
The fourth argument is a closure,
第四个参数是一个闭包,

559
00:25:45,511 --> 00:25:47,644
So you sign up for this radio station and
你注册这个电台

560
00:25:47,712 --> 00:25:51,281
when there are broadcasts this closure get to executed,
当有广播这个闭包去执行,

561
00:25:51,350 --> 00:25:52,516
And that queue is
队列是

562
00:25:52,585 --> 00:25:54,984
what queue that closure get to execute it on,
关闭队列得到执行,

563
00:25:55,053 --> 00:25:56,720
If you say nil, by the way, for
如果你说nil,顺便说一下,

564
00:25:56,788 --> 00:26:00,290
that queue you get executed on the same queue that
这个队列上执行相同的队列

565
00:26:00,359 --> 00:26:04,094
the radio station broadcaster is broadcasting on, but
广播电台电视台,但是

566
00:26:04,163 --> 00:26:06,830
very often here you're gonna be doing UI stuff,
经常在这,你会做UI的东西,

567
00:26:06,899 --> 00:26:10,467
In which case, you wanna put operation,mainqueue here,
在这种情况下,你想把操作,mainqueue这里,

568
00:26:10,535 --> 00:26:13,036
Operation,main, I think is, is what it was called,
我认为,操作,主要是它叫什么,

569
00:26:13,105 --> 00:26:15,372
Cuz you obviously need to be on main queue
因为你显然需要主要队列上

570
00:26:15,441 --> 00:26:16,973
to do any UI work,
UI做任何工作,

571
00:26:17,042 --> 00:26:18,775
So inside this closure, you can see there's one
所以在这个闭包中,您可以看到有一个

572
00:26:18,844 --> 00:26:21,077
argument which is notification,
论证的通知,

573
00:26:21,146 --> 00:26:24,080
That is the broadcast packet,
广播包,

574
00:26:24,149 --> 00:26:27,150
if you wanna think of it that was broadcast, and
如果你想把它播出,和

575
00:26:27,219 --> 00:26:29,653
inside there there's a couple of things but the really
里面有很多但是真正的东西

576
00:26:29,721 --> 00:26:32,689
important thing is something called the user info,
重要的是所谓的用户信息,

577
00:26:32,758 --> 00:26:34,758
See that notification,userInfo,
看到通知,用户信息,

578
00:26:34,827 --> 00:26:37,660
That's a dictionary that the broadcaster
这是一个电视台的字典

579
00:26:37,729 --> 00:26:40,497
can put any information they want for
可以把他们想要的任何信息

580
00:26:40,566 --> 00:26:42,299
people who are listening to this radio station,
人听这个电台,

581
00:26:43,836 --> 00:26:46,236
We'll have some examples to see what kind of stuff people
我们会有一些什么样的人

582
00:26:46,305 --> 00:26:47,904
put in their user info,
放在他们的用户信息,

583
00:26:47,973 --> 00:26:50,607
So that's it, super straightforward,
就是这样,超级简单,

584
00:26:50,676 --> 00:26:52,842
This is how you listen to a radio station,
这就是你听一个电台,

585
00:26:52,911 --> 00:26:56,313
So let's see, before I show you an example of it,
我们看看,之前我给你一个例子,

586
00:26:56,382 --> 00:26:58,148
let's talk about NSNotification,Name,
让我们来谈谈NSNotification、名称、

587
00:26:59,518 --> 00:27:01,552
Its types like this which is really nice and
这样很好的,它的类型

588
00:27:01,620 --> 00:27:05,088
swift in iOS 10 they really typed
斯威夫特在iOS 10他们真的类型

589
00:27:05,157 --> 00:27:08,992
all of the things used to be just string, have been type so
使用的所有事情只是字符串,所以一直类型

590
00:27:09,061 --> 00:27:11,061
you know what type of thing you're looking for here,
你知道什么类型的东西你正在寻找,

591
00:27:11,130 --> 00:27:15,431
NSNotification,Name, what's really cool about that,
NSNotification,名字,很酷,

592
00:27:15,500 --> 00:27:16,966
is if you go look at the documentation,
如果你去看文档,

593
00:27:17,035 --> 00:27:20,103
for NSNotification,Name, you'll see all
NSNotification,名字,你会看到所有

594
00:27:20,172 --> 00:27:23,906
of the radio stations that iOS will broadcast on,
iOS的广播电台播放,

595
00:27:23,975 --> 00:27:25,875
And there's a lot of them,
有很多的,

596
00:27:25,944 --> 00:27:28,412
But it's a great way to quickly learn what radio
但这是一个很好的方法来快速了解收音机

597
00:27:28,480 --> 00:27:31,315
stations there are built into IOS,
站有内置IOS,

598
00:27:33,218 --> 00:27:36,286
They're all static vars, these names of the radio stations
他们都是静态的var,这些名字的广播电台

599
00:27:36,355 --> 00:27:38,255
are static vars in NSNOtification,Name,
是静态的var NSNOtification、名称、

600
00:27:38,323 --> 00:27:41,458
Now you can create your own NSNotification,Name, because
现在,您可以创建自己的NSNotification,名字,因为

601
00:27:41,527 --> 00:27:43,727
it's perfectly legal to create your own radio station, and
这是完全合法的创建自己的广播电台,和

602
00:27:43,795 --> 00:27:45,128
broadcast if you want,
如果你愿意,广播

603
00:27:45,197 --> 00:27:48,565
You just do that with the string initializer for
你只是这样的字符串初始化

604
00:27:48,634 --> 00:27:50,667
the type NSNotification,Name,
NSNotification类型、名称、

605
00:27:50,736 --> 00:27:53,904
NSNotification,Name, hopefully by now you're familiar after
NSNotification,名字,希望现在你熟悉后

606
00:27:53,973 --> 00:27:55,204
reading your reading assignments and
读你的阅读作业

607
00:27:55,273 --> 00:27:58,142
stuff, it's just a nested class, name,
东西,它只是一个嵌套类,名字,

608
00:27:58,210 --> 00:28:01,878
it's a instruct or something inside NSNotification,
这是一个指示NSNotification内什么的,

609
00:28:01,947 --> 00:28:06,483
That's why it's NSNotification,Name,
这就是为什么NSNotification、名称、

610
00:28:06,551 --> 00:28:08,886
So I'll talk about broadcasting in a second,
所以我将讨论广播,

611
00:28:08,954 --> 00:28:11,688
But first I wanna show you an example of listening,
但首先我要告诉你听的一个例子,

612
00:28:11,756 --> 00:28:15,058
So here's a radio station, a system radio station called
这是一个广播电台,广播电台

613
00:28:15,127 --> 00:28:17,361
UIContentSizeCategoryDidCha- nge,
UIContentSizeCategoryDidCha字,

614
00:28:17,429 --> 00:28:19,829
you see it there under the forName,
你看到它在forName下,

615
00:28:19,898 --> 00:28:23,032
And this if you go into your settings app on your phone and
这如果你进入应用在你的手机和你的设置

616
00:28:23,101 --> 00:28:27,271
go under accessibility you'll see that there is a text size
破产可访问性你会发现有一个文本的大小

617
00:28:27,339 --> 00:28:29,806
setting, looks like the thing on the right there,
设置,看起来像右边的东西,

618
00:28:29,875 --> 00:28:31,374
where you can set the size of your text,
你在哪里可以设置文本的大小,

619
00:28:31,443 --> 00:28:34,110
So when you get old like me you can make the text
所以当你变老喜欢我你可以使文本

620
00:28:34,179 --> 00:28:34,845
a little bit bigger and
大一点

621
00:28:34,913 --> 00:28:37,214
still see without having any reading glasses,
仍然看到没有任何阅读眼镜,

622
00:28:37,282 --> 00:28:39,315
When your young like you you can make it really small so
当你像你这样的年轻你可以让它很小

623
00:28:39,384 --> 00:28:42,152
you can get more text on screen,
你可以得到更多的文本在屏幕上,

624
00:28:42,221 --> 00:28:46,389
So, when that changes though all the apps
所以,当改变尽管所有的应用程序

625
00:28:46,458 --> 00:28:50,460
find out about it and each of them then locally broadcast on
发现和他们每个人在本地播放

626
00:28:50,529 --> 00:28:51,928
this radio station,
这个电台,

627
00:28:51,997 --> 00:28:53,530
Now, radio stations are only used for
现在,电台只用于

628
00:28:53,599 --> 00:28:55,732
broadcasting inside your app,
广播在你的应用程序,

629
00:28:55,800 --> 00:28:59,803
So the communication from iOS the operating system
所以从iOS操作系统通信

630
00:28:59,872 --> 00:29:03,106
to the apps that this changed is happening some other way,
应用这其他方式正在发生改变,

631
00:29:03,174 --> 00:29:04,841
You don't know what it is, it's behind the scenes,
你不知道它是什么,它是在幕后,

632
00:29:04,909 --> 00:29:05,842
you don't care,
你不在乎,

633
00:29:05,910 --> 00:29:09,245
But when an app finds out that this slider has changed,
但是当一个应用程序发现这个滑块已经改变,

634
00:29:09,314 --> 00:29:12,682
it locally broadcasts on this radio station UI content size
在本地广播电台UI内容大小

635
00:29:12,751 --> 00:29:13,817
category did change,
类别做了改变,

636
00:29:13,886 --> 00:29:16,887
Because those little, that slider actually has, like,
因为那些小滑块有,,

637
00:29:16,956 --> 00:29:19,956
detant marks on there, and it's not just, like,
detant痕迹,这不仅仅是,喜欢,

638
00:29:20,025 --> 00:29:21,391
the point size or the font,
点大小或字体,

639
00:29:21,460 --> 00:29:25,161
It's small, medium, large, extra large,
小型,中型,大型,额外的大,

640
00:29:25,230 --> 00:29:26,396
extra extra large,
额外的超大,

641
00:29:26,464 --> 00:29:30,366
So, as you slide that thing across,
所以,当你在幻灯片的事,

642
00:29:30,435 --> 00:29:31,968
So if I want to hear about that change,
所以如果我想听到这一变化,

643
00:29:32,037 --> 00:29:34,404
now why would I want to hear that this is changing?
为什么我想要听到的,这是改变?

644
00:29:34,473 --> 00:29:37,140
I don't need to hear it from my fonts because
我不需要从我的字体,因为听到它

645
00:29:37,209 --> 00:29:38,575
I'm being a good programmer and
我是一个优秀的程序员

646
00:29:38,643 --> 00:29:42,112
I'm using the text styles in my UI,
我使用我的UI中的文本样式,

647
00:29:42,180 --> 00:29:44,214
Remember when we went to the UI and
还记得我们去了UI和

648
00:29:44,283 --> 00:29:47,350
we set the text style to be like body font or
我们设置了身体的字体或文本样式

649
00:29:47,419 --> 00:29:49,953
headline font, or caption font, remember when we were
标题字体,标题字体,还记得我们

650
00:29:50,021 --> 00:29:53,556
doing the little Tweet Twitter client there?
做小微博Twitter客户端吗?

651
00:29:53,625 --> 00:29:57,494
So those will automatically get updated when this changes,
这将自动得到更新当这个变化,

652
00:29:57,562 --> 00:30:00,163
But what if I have something else an icon or
但是,如果我有别的一个图标或

653
00:30:00,232 --> 00:30:03,266
some other image that really wants to size itself depending
一些其他的图像本身真的想大小不同

654
00:30:03,335 --> 00:30:04,400
on the surrounding text,
在周围的文本,

655
00:30:04,469 --> 00:30:06,870
If the text gets really small maybe the icon wants to
如果文本也许图标想真的很小

656
00:30:06,939 --> 00:30:07,855
if the text gets really big the icon wants to get bigger,
如果图标变得很大的文本想要变大,

657
00:30:07,856 --> 00:30:08,772
get smaller,
变得越来越小,

658
00:30:08,841 --> 00:30:12,876
So I might want to find out, so I find out by signing
所以我想找到答案,所以我找出签署

659
00:30:12,945 --> 00:30:16,880
up to listen to this radio station with addObserver,
与addObserver听这个电台,

660
00:30:16,949 --> 00:30:19,515
And here I'm saying I'm only
我说我只

661
00:30:19,584 --> 00:30:22,685
interested if the UI application object sends it,
感兴趣如果UI应用程序对象发送它,

662
00:30:22,754 --> 00:30:25,188
I can probably put nil there actually cuz I don't care who
我可以把零实际上因为我不在乎

663
00:30:25,257 --> 00:30:28,591
sends this I know it's going to be the application object,
发送这我知道这将是应用程序对象,

664
00:30:28,660 --> 00:30:29,993
but I don't really care,
但我不在乎,

665
00:30:30,061 --> 00:30:32,662
And I am going to execute this on the main queue because
我要执行这个主队列,因为

666
00:30:32,731 --> 00:30:34,531
I am going to do UI things for
我要做UI的东西

667
00:30:34,599 --> 00:30:37,968
sure, in reaction to that size category changing,
当然,在反应大小类别发生变化,

668
00:30:38,036 --> 00:30:41,537
And then inside my closure I look at the notification and
然后在我关闭我看通知

669
00:30:41,606 --> 00:30:44,941
in the dictionary there I'm looking for the key called
在字典里有我要找的关键

670
00:30:45,009 --> 00:30:49,011
UIContentSizeCategoryNewValue- Key,
UIContentSizeCategoryNewValue -键,

671
00:30:49,080 --> 00:30:50,513
And I found out about that
我发现了这一点

672
00:30:50,582 --> 00:30:52,182
by looking in the documentation under
通过在文档中

673
00:30:52,251 --> 00:30:55,585
NSNotification,Name,UIContent- SizeCategoryDidChange,
NSNotification、名称、UIContent SizeCategoryDidChange,

674
00:30:55,654 --> 00:30:58,688
And when I looked at that particular radio station,
当我看着那个特定的广播电台,

675
00:30:58,757 --> 00:30:59,723
It said in the documentation,
在文档中,

676
00:30:59,792 --> 00:31:02,459
hey, you can use UIContentSizeCategoryNewValu-
嘿,你可以使用UIContentSizeCategoryNewValu -

677
00:31:02,528 --> 00:31:05,896
eKey to get out of the dictionary the size category,
eKey字典大小的类别,

678
00:31:05,964 --> 00:31:08,297
In other words the position of that slider,
换句话说,滑块的位置,

679
00:31:08,366 --> 00:31:10,767
And so an example what the value might be of that would
所以一个例子可能的价值

680
00:31:10,836 --> 00:31:13,170
be UIContentSizeCategorySmall,
UIContentSizeCategorySmall,

681
00:31:15,073 --> 00:31:16,706
So now I found out, and
现在我发现,

682
00:31:16,775 --> 00:31:18,174
I'll find out every time that changes,
我会找到的每一次变化,

683
00:31:18,243 --> 00:31:20,677
I'll get a broadcast and it'll tell me,
我将得到一个广播,它会告诉我,

684
00:31:20,746 --> 00:31:22,212
Now, I didn't really talk about this, but
现在,我真的不谈论这个,但是

685
00:31:22,281 --> 00:31:25,381
notice that addObserver, that notification,
请注意,addObserver通知,

686
00:31:25,450 --> 00:31:28,618
default notification center method, it returned something,
默认的通知中心方法,它返回,

687
00:31:28,687 --> 00:31:33,223
This thing observer, which is of type NS object protocol,
这个观察者,NS对象类型的协议,

688
00:31:33,292 --> 00:31:34,958
Basically it's a cookie,
基本上这是一块饼干,

689
00:31:35,026 --> 00:31:35,859
You don't what it is,
你不什么,

690
00:31:35,927 --> 00:31:38,728
you don't know what type it is, all you use it for,
你不知道型号,你用它来,

691
00:31:38,797 --> 00:31:41,498
is later when you're no longer interested in hearing about
以后当你不再感兴趣呢

692
00:31:41,567 --> 00:31:44,033
this, you remove this observer,
这个,你把这个观察者,

693
00:31:44,102 --> 00:31:47,370
That's, that's saying to the notification center,
这是,这是对通知中心说,

694
00:31:47,438 --> 00:31:49,473
I don't wanna hear about this radio station anymore, so
我不想听到关于这个电台了,

695
00:31:49,541 --> 00:31:51,174
don't send me anymore broadcasts,
不再给我广播,

696
00:31:51,243 --> 00:31:55,312
Now it's really important to do that,
现在是非常重要的,

697
00:31:55,380 --> 00:31:58,482
So usually we're going to do something UI-oriented
通常我们会做一些UI-oriented

698
00:31:58,550 --> 00:32:02,518
like this,
像这样,

699
00:32:02,587 --> 00:32:04,121
And then in view will disappear,
然后在视图将会消失,

700
00:32:04,189 --> 00:32:06,456
we're gonna remove observer because it makes no sense to
我们将删除观察者,因为它毫无意义

701
00:32:06,525 --> 00:32:09,192
listen to this radio station and adjust our icon sizes and
听这个电台和大小和调整我们的图标

702
00:32:09,261 --> 00:32:11,761
stuff when we're not on screen,
东西时,我们不是在屏幕上,

703
00:32:11,829 --> 00:32:15,031
Now of course, this might happen while we're off screen,
当然,这可能发生在我们离开屏幕,

704
00:32:15,100 --> 00:32:19,902
So perhaps in our view did appear, or view will appear,
也许在我们看来确实出现,或视图将会出现,

705
00:32:19,971 --> 00:32:22,973
we might want to adjust our icon sizes based on
我们想调整我们的图标大小的基础上

706
00:32:23,042 --> 00:32:24,307
this content size category,
这个内容大小类别,

707
00:32:24,376 --> 00:32:26,276
Which you can get that from the UI application,
你可以得到从UI应用程序,

708
00:32:26,345 --> 00:32:28,044
you can just ask it what it is and it will tell you,
你可以问它是什么和它会告诉你,

709
00:32:28,113 --> 00:32:31,981
you don't have to, have to get a radio station notification,
你不需要,必须得到一个电台通知,

710
00:32:32,050 --> 00:32:33,317
to find out what it is,
找出它是什么,

711
00:32:34,919 --> 00:32:37,320
That's an example of listening to a radio station,
这是听一个电台的一个例子,

712
00:32:37,388 --> 00:32:41,024
Now what about sending on a radio station, broadcasting,
现在发送广播电台,广播,

713
00:32:41,093 --> 00:32:42,259
That's super simple, as well,
这是超级简单,

714
00:32:42,327 --> 00:32:44,193
You get that default notification center, and
你得到默认的通知中心,

715
00:32:44,262 --> 00:32:46,663
you're gonna use the method post,
你会使用方法后,

716
00:32:46,732 --> 00:32:49,433
Post takes the name of the radio station to post on,
文章需要广播电台发布的名称,

717
00:32:49,501 --> 00:32:52,402
which again, you can invent your own if you want,
再次,你可以发明自己的如果你愿意的话,

718
00:32:52,471 --> 00:32:55,838
The object, that's the sender, in case people might only be
的对象,发送方,以防人可能只有

719
00:32:55,907 --> 00:32:58,975
interested in this being broadcast from certain people,
这从某些人广播感兴趣,

720
00:32:59,044 --> 00:33:01,278
Usually, this would be self, that you would put there,
通常,这将是自我,你将在那里,

721
00:33:02,314 --> 00:33:03,713
And then there's the user info,
还有用户信息,

722
00:33:03,782 --> 00:33:06,983
That's that dictionary that you get to pass to them,
这就是你得到那本字典传给他们,

723
00:33:07,052 --> 00:33:08,919
So, that's the same user info they're gonna get,
所以,这是他们会得到相同的用户信息,

724
00:33:10,923 --> 00:33:14,691
So, as soon as you execute this post
所以,当你执行这篇文章

725
00:33:14,759 --> 00:33:18,861
all listeners, all people who did addObserver, who
addObserver,所有听众,所有人

726
00:33:18,930 --> 00:33:21,864
are listening on, for their closure to execute on the same
关闭监听,他们执行的一样吗

727
00:33:21,933 --> 00:33:25,202
queue as your posting this on will immediately execute,
队列作为发布这将立即执行,

728
00:33:27,705 --> 00:33:29,072
All the other ones, so
所有其他的,所以

729
00:33:29,140 --> 00:33:31,040
if you're posting this off the main queue for
如果你发布了主队列

730
00:33:31,109 --> 00:33:34,344
example and you're observers are all on the main queue,
例子,你观察人士都在主队列,

731
00:33:34,412 --> 00:33:36,679
Their closures will just be put on the queue,
闭包就是放在队列中,

732
00:33:36,748 --> 00:33:38,648
they'll be put on the main queue, and
他们会把主要的队列上,

733
00:33:38,717 --> 00:33:41,685
they'll execute the next opportunity that they have,
他们将执行下一个机会,

734
00:33:44,522 --> 00:33:47,324
So that's it, posting and posting to broadcasts on
就是这样,上传和发布广播

735
00:33:47,392 --> 00:33:50,193
the radio station, by the way radio station that's just
电台,电台的

736
00:33:50,262 --> 00:33:52,395
something I made up, nobody calls it that,
我了,没人管它叫

737
00:33:52,464 --> 00:33:54,364
you're not gonna see that in the docs,
你不会看到在文档,

738
00:33:54,433 --> 00:33:57,033
it's just a analogy for what's going on here,
这只是一个比喻,这是怎么回事

739
00:33:57,101 --> 00:33:59,136
That's notifications,
的通知,

740
00:33:59,204 --> 00:34:02,739
There's another kind of radio station model thing,
还有电台模型的另一种事,

741
00:34:02,808 --> 00:34:06,609
which I'm not talking about, which is key value observing,
我并不是在谈论,键值观察,

742
00:34:06,678 --> 00:34:09,545
And you might wanna look up in the docs as well,
你可能会想要查找的文档,

743
00:34:09,614 --> 00:34:13,583
That's a way that you can sign up to find out if a var
这是一种你可以注册发现如果一个var

744
00:34:13,652 --> 00:34:15,819
on some other object changes,
在其他对象的变化,

745
00:34:17,989 --> 00:34:20,590
So, take a look at that if you might be interested in that,
所以,看一看,如果你可能会感兴趣,

746
00:34:22,660 --> 00:34:25,695
The next topic here is the application life cycle,
这里的下一个主题是应用程序生命周期,

747
00:34:25,764 --> 00:34:27,397
You know how we have a view life cycle,
你知道我们有一个生命周期,

748
00:34:27,465 --> 00:34:29,799
we have an application one too and you get to find out as
我们也有一个应用程序,你可以找到

749
00:34:29,868 --> 00:34:31,934
your application goes through its life cycle,
您的应用程序通过它的生命周期,

750
00:34:32,003 --> 00:34:35,472
So first let me talk about the states that your application
首先让我谈谈您的应用程序的状态

751
00:34:35,540 --> 00:34:36,139
can be in,
可以的,

752
00:34:36,207 --> 00:34:39,743
It can be in really one of five conditions,
它可以在真正的五个条件,

753
00:34:39,812 --> 00:34:42,411
One is the top not running,
一个是前未运行,

754
00:34:42,480 --> 00:34:43,779
So that's, user has never,
所以,用户从来没有,

755
00:34:43,848 --> 00:34:46,415
not run your app, obviously you're not running,
没有运行你的应用,显然你不运行,

756
00:34:46,484 --> 00:34:48,885
Your code, there's no code executing in
您的代码,没有代码执行

757
00:34:48,954 --> 00:34:50,620
any way related to your app,
任何方式与应用程序有关,

758
00:34:50,689 --> 00:34:52,355
No one's touched on your icon or anything,
没有人提到了你的图标,

759
00:34:54,025 --> 00:34:56,893
Then there's two foreground states
有前景的两个州

760
00:34:56,962 --> 00:34:59,095
after your app starts running,
你的应用程序开始运行后,

761
00:34:59,163 --> 00:35:01,397
One is called the inactive state,
一个叫做不活跃的状态,

762
00:35:01,466 --> 00:35:03,867
In the inactive state, you don't get any events,
在非活动状态,你得不到任何的事件,

763
00:35:03,935 --> 00:35:05,568
You can't draw any UI,
你不能得出任何UI,

764
00:35:05,637 --> 00:35:09,305
You're just kind of like preparing to, to really run,
你只是有点像准备,真正运行,

765
00:35:09,374 --> 00:35:10,273
You're not active,
你不主动,

766
00:35:10,342 --> 00:35:12,041
You're not being shown on screen,
你没有被显示在屏幕上,

767
00:35:12,110 --> 00:35:14,244
The user's not interacting with you,
用户不是与你交流,

768
00:35:14,313 --> 00:35:17,113
The other one the other foreground state is active,
另一个另一个前景状态是活跃的,

769
00:35:17,182 --> 00:35:19,515
now this is the normal state where you're getting
这是你要的正常状态

770
00:35:19,584 --> 00:35:22,119
touch events, you're drawing on screen, you're interacting
触摸事件,你画在屏幕上,相互作用的

771
00:35:22,187 --> 00:35:25,188
user perceives you as an active application,
积极应用程序用户感知,

772
00:35:26,859 --> 00:35:29,059
Then there's also the background state,
然后还有背景状态,

773
00:35:29,127 --> 00:35:32,728
Now the background state is even less running than
现在后台运行甚至低于状态

774
00:35:32,797 --> 00:35:37,533
the foreground inactive state, in the background state you're
前台不活跃的状态,你在后台状态

775
00:35:37,602 --> 00:35:41,705
clearly not on screen and not only are you not on screen and
显然不是在屏幕上,不仅会使你的屏幕上

776
00:35:41,773 --> 00:35:46,008
interacting you're barely running in the background and
你几乎在后台运行,进行交互

777
00:35:46,077 --> 00:35:48,445
your lifetime there is limited,
你的一生是有限的,

778
00:35:48,513 --> 00:35:51,548
You're probably not gonna run for more than 30 seconds,
你可能不会超过30秒,

779
00:35:51,616 --> 00:35:54,417
This is a transitory state between
这是一个暂时的状态之间

780
00:35:54,486 --> 00:35:55,585
being in the foreground and
在前台

781
00:35:55,654 --> 00:35:57,419
going to the next state I'm gonna talk about,
进入下一状态我要讲,

782
00:35:57,488 --> 00:35:58,989
which is to be suspended,
暂停,

783
00:36:00,225 --> 00:36:01,624
So, if you're suspended,
所以,如果你暂停,

784
00:36:01,693 --> 00:36:04,561
no code in your application is running,
没有代码在您的应用程序正在运行,

785
00:36:04,630 --> 00:36:06,629
You're still in memory, but
你仍然在内存中,但是

786
00:36:06,698 --> 00:36:08,264
you're just sitting there not running,
你只是坐在那里不运行,

787
00:36:08,333 --> 00:36:09,499
You get no cycles,
你没有得到周期,

788
00:36:11,069 --> 00:36:15,137
Now, one thing you have to be, you have to kind of understand
现在,有一件事你必须,你必须理解

789
00:36:15,206 --> 00:36:18,074
about how this life cycle works is that you transition
这个生命周期是如何工作的是你过渡

790
00:36:18,143 --> 00:36:20,911
through these states in an orderly fashion,
通过这些州以有序的方式,

791
00:36:20,979 --> 00:36:23,480
So when you launch, you go from not running,
所以当你启动,你从没有跑步,

792
00:36:23,548 --> 00:36:25,849
to this foreground inactive state, to active,
这种前景不活跃的状态,活跃,

793
00:36:25,917 --> 00:36:29,819
You always transition through inactive to get to active,
通过活动来活跃你总是过渡,

794
00:36:29,888 --> 00:36:32,922
When some other app is switched to, someone launches
切换到其他应用程序时,有人发射

795
00:36:32,991 --> 00:36:35,858
another app and you're the you were the active app, you go
另一个应用程序,你的积极应用,你走

796
00:36:35,927 --> 00:36:39,428
from active back to inactive in the foreground briefly,
从活跃不活跃在前台,

797
00:36:39,497 --> 00:36:44,300
then around down to background for up to 30 seconds or
然后大约为30秒或背景

798
00:36:44,369 --> 00:36:47,603
so and then you get suspended where you don't run at all,
然后你会暂停,你别跑,

799
00:36:47,672 --> 00:36:50,373
So you always transition through that flow to go
所以你总是过渡流去

800
00:36:50,441 --> 00:36:53,276
from you're the active app to somebody else's
从你积极应用到别人的

801
00:36:53,345 --> 00:36:55,144
the other deactive app,
其他不激活应用程序,

802
00:36:55,213 --> 00:36:59,149
Now when you're in suspended state and
现在,当你在暂停状态

803
00:36:59,217 --> 00:37:01,718
you get killed for whatever reason,
你杀了不管是什么原因,

804
00:37:01,786 --> 00:37:05,287
You go straight to killed and no code of yours runs from
你直接死亡,没有你的代码运行

805
00:37:05,356 --> 00:37:08,224
the time you're suspended, to the time you get killed,
时间你暂停,你被杀死的时候,

806
00:37:08,292 --> 00:37:09,526
Why do you get killed?
你为什么被杀?

807
00:37:09,594 --> 00:37:12,395
Well, maybe the user killed you, explicitly,
也许用户杀了你,明确,

808
00:37:12,463 --> 00:37:14,097
Maybe you started using too much memory and
也许你开始使用太多内存和

809
00:37:14,165 --> 00:37:15,064
the system killed you,
杀了你,

810
00:37:15,133 --> 00:37:18,401
Maybe the phone's battery died, it got re-booted, for
也许手机电池死了,重启了,

811
00:37:18,469 --> 00:37:19,735
some reason, whatever,
某些原因,无论如何,

812
00:37:19,804 --> 00:37:21,604
So when you're in the suspended state,
所以当你在暂停状态,

813
00:37:21,673 --> 00:37:23,773
you kind of have to be ready to just be killed,
你不得不准备就被杀死,

814
00:37:23,841 --> 00:37:26,275
So you wouldn't want to have any unsaved data, or
所以你不想有任何未保存的数据,或

815
00:37:26,344 --> 00:37:27,744
anything else going on in that state,
其他的国家,

816
00:37:27,813 --> 00:37:29,779
that's why you get the background state,
这就是为什么你得到背景状态,

817
00:37:29,848 --> 00:37:30,947
to kinda get ready for that,
有点准备,

818
00:37:32,250 --> 00:37:35,017
Now, at each of these arrows, these orange arrows,
现在,在每一个箭头,这些橙色箭头,

819
00:37:35,086 --> 00:37:39,622
you get a message sent to your application delegate,
你得到一个消息发送到应用程序委托,

820
00:37:39,691 --> 00:37:41,190
So far, we've only used the application
到目前为止,我们只使用应用程序

821
00:37:41,259 --> 00:37:44,627
delegate to have our little core data stuff in there,
委托我们的小核心数据的东西在里面,

822
00:37:44,696 --> 00:37:45,895
But there's a bunch of methods in there,
但是有很多方法,

823
00:37:45,964 --> 00:37:48,064
You've seen them every time you look and you had delegate,
你看过他们每次你看,你有委托,

824
00:37:48,133 --> 00:37:50,233
And we're gonna talk about what they all do and
我们要谈论什么都做

825
00:37:50,302 --> 00:37:51,534
when they're all called,
当他们都是调用时,

826
00:37:51,603 --> 00:37:54,737
So the first one in your app delegate is called application
首先在应用程序委托调用的应用程序

827
00:37:54,806 --> 00:37:56,773
didFinishLaunchingWithOptions,
didFinishLaunchingWithOptions,

828
00:37:56,842 --> 00:37:57,407
There's also
也有

829
00:37:57,475 --> 00:37:59,241
a willFinishLaunchingWithOpti- ons,
willFinishLaunchingWithOpti——国家统计局,

830
00:37:59,310 --> 00:38:01,510
And it gives you this dictionary,
这本字典给你,

831
00:38:01,579 --> 00:38:02,144
And the dictionary,
和字典,

832
00:38:02,213 --> 00:38:04,647
the keys are UIApplicationLaunchOptionsKey,
键是UIApplicationLaunchOptionsKey,

833
00:38:04,715 --> 00:38:07,216
which you can look in the documentation for that symbol,
你可以在文档中寻找,象征,

834
00:38:07,285 --> 00:38:09,318
And you'll find all the various things that can appear
,你会发现各种可能出现的事情

835
00:38:09,387 --> 00:38:10,486
in this dictionary,
在这本字典,

836
00:38:10,555 --> 00:38:13,456
And the values depend on what the key is,
和的值取决于什么是关键,

837
00:38:13,525 --> 00:38:15,491
By the way, all of these app delegate methods,
顺便说一下,所有的这些应用程序委托方法,

838
00:38:15,560 --> 00:38:19,195
you can also get by listening to this radio stations,
你也可以通过听这个广播电台,

839
00:38:19,264 --> 00:38:20,396
So the radio station for
因此,广播电台

840
00:38:20,465 --> 00:38:22,965
this one is the UIApplicationDidFinishLauching
这一个是UIApplicationDidFinishLauching

841
00:38:23,034 --> 00:38:25,969
radio station and it's notification ,name,that If you
广播电台通知,名字,如果你

842
00:38:26,037 --> 00:38:28,704
listen to that you'll get, and you do add observer,
你会听,你添加的观察者,

843
00:38:28,773 --> 00:38:31,474
you'll get your closer called when did launch finish
你会得到你叫什么时候启动完成

844
00:38:31,543 --> 00:38:34,277
launching happens, so you don't have to put it in your
启动发生,所以你不必把它放在你的

845
00:38:34,346 --> 00:38:38,014
app delegate you could put it in other places other code,
应用委托你可以把它放在其他地方其他代码,

846
00:38:38,083 --> 00:38:41,384
What happens here in this DidFinishLaunchWithOptions
发生了什么在这个DidFinishLaunchWithOptions

847
00:38:41,452 --> 00:38:44,086
what why does it get called things like that,
为什么它被调用,

848
00:38:44,155 --> 00:38:46,489
why do you have this dictionary?
为什么你有这本字典吗?

849
00:38:46,557 --> 00:38:49,559
Well, obviously when you normally launch, this gets
显然,正常启动时,这个会

850
00:38:49,627 --> 00:38:52,361
called, the dictionary doesn't have anything in it,
调用时,字典没有任何关系,

851
00:38:52,430 --> 00:38:53,697
Because you just got launch normally,
因为你刚刚启动正常,

852
00:38:53,765 --> 00:38:55,764
the user clicked on your icon and launched,
用户点击图标和启动,

853
00:38:55,833 --> 00:38:57,200
But there are a lot of other ways for
但是有很多其他的方法

854
00:38:57,269 --> 00:38:59,435
you to get launch to buy the system,
你推出购买系统,

855
00:38:59,504 --> 00:39:01,304
And when those other ways happen,
当其他方式发生,

856
00:39:01,372 --> 00:39:03,405
then you're gonna have this dictionary to tell you why,
那么你会有这本字典告诉你为什么,

857
00:39:03,474 --> 00:39:05,407
and give you the information you need,
和给你你需要的信息,

858
00:39:05,476 --> 00:39:07,110
So one thing, for example,
举例来说,这样一件事

859
00:39:07,178 --> 00:39:10,112
is if your application opens a certain kind of document,
如果您的应用程序打开一个特定类型的文档,

860
00:39:10,181 --> 00:39:12,682
let's say you're a PDF viewer and you know how to open PDF
假设你是一个PDF查看器,你知道如何打开PDF

861
00:39:12,750 --> 00:39:15,551
files and you've registered that with the system,
与系统文件和你注册,

862
00:39:15,620 --> 00:39:18,287
Then if someone in some other app says, open this PDF,
然后说如果有人在其他一些应用程序,打开这个PDF,

863
00:39:18,356 --> 00:39:21,157
the system's gonna launch you,
系统会启动你,

864
00:39:21,225 --> 00:39:23,826
And when it launches you, in the dictionary right there
当它启动,在字典里

865
00:39:23,894 --> 00:39:26,729
is gonna be that URL with some key,
将该URL与一些关键

866
00:39:26,798 --> 00:39:28,464
It's telling you to open it,
它告诉你打开它,

867
00:39:28,533 --> 00:39:32,068
And so that's an example, another one is,
这就是一个例子,另一个是,

868
00:39:32,136 --> 00:39:34,403
you have set up, you can set up with core location,
你有设置,您可以设置核心位置,

869
00:39:34,472 --> 00:39:37,706
I didn't get to talk about core location this quarter,
我没有谈论本季度核心位置,

870
00:39:37,775 --> 00:39:41,443
but you can set up a core location mechanism, whereby,
但是你可以建立一个核心位置的机制,即,

871
00:39:41,512 --> 00:39:44,614
if you go by someplace in the world, the dry cleaner,
如果你去世界上的某个地方,干洗店,

872
00:39:44,683 --> 00:39:46,382
just the canonical example,
典型的例子,

873
00:39:46,451 --> 00:39:50,052
when you walk by the dry cleaner, your app will launch,
当你走到干洗店,应用程序将启动,

874
00:39:50,121 --> 00:39:52,422
So you could set it up and if that happens again,
所以你可以设置它,如果出现这种情况,

875
00:39:52,490 --> 00:39:55,258
this dictionary will say, hey I launched you because you
这本词典会说,嘿,我了你,因为你

876
00:39:55,326 --> 00:39:57,460
went to one of your registered locations and
去你的一个位置和注册

877
00:39:57,529 --> 00:39:59,462
here it is when you worked,
这是你工作的时候,

878
00:39:59,530 --> 00:40:02,998
You can also do it for continuing activities,
也可以继续活动,

879
00:40:03,067 --> 00:40:04,700
I don't know if you guys know about this feature,
我不知道你们是否知道这个特性,

880
00:40:04,769 --> 00:40:05,735
it's kind of a nice feature,
这是一种不错的功能,

881
00:40:05,804 --> 00:40:08,371
You start browsing something on your phone, and
你开始浏览的东西在你的手机上

882
00:40:08,439 --> 00:40:09,672
then you switch over to your iPad,
然后切换到你的iPad,

883
00:40:09,741 --> 00:40:12,241
You can continue browsing from exactly where you were,
你从哪里你可以继续浏览,

884
00:40:12,310 --> 00:40:14,410
So you might get launched to do that,
所以你可能会推出,

885
00:40:14,479 --> 00:40:16,712
to continue doing what you were doing,
继续做你所做,

886
00:40:16,781 --> 00:40:18,881
If you get a push notification,
如果你得到一个通知,

887
00:40:18,950 --> 00:40:22,885
we didn't really talk about notifications much except for
我们没有谈论通知除外

888
00:40:22,954 --> 00:40:25,421
in the cloud kit section, I hope you,
云中的设备部分,我希望你,

889
00:40:25,489 --> 00:40:28,725
how many of you saw the cloud kit Friday section?
你们中有多少人看到云工具包周五部分?

890
00:40:28,793 --> 00:40:32,194
It's only a few of you, it's worth going back and looking
只有少数的你,值得去看

891
00:40:32,263 --> 00:40:34,898
at just to see notifications and push notifications,
在看到通知和推送通知,

892
00:40:34,966 --> 00:40:38,134
But if you get a push notification sent to you and
但如果你得到一个推送通知发送给你

893
00:40:38,203 --> 00:40:39,602
your app's not running,
你的应用程序不运行,

894
00:40:39,671 --> 00:40:42,905
it may get launched to handle that thing,
它可能会推出去处理那件事,

895
00:40:42,974 --> 00:40:45,908
Or if you have some Bluetooth device that you connect with,
或者如果你有一些你连接的蓝牙设备,

896
00:40:45,977 --> 00:40:48,110
it, it gets in range and it gets launched,
它,它就在范围和启动,

897
00:40:48,179 --> 00:40:49,111
So there's a lot of reasons your
所以你有很多的原因

898
00:40:49,180 --> 00:40:50,179
application might get launched,
应用程序可能会启动,

899
00:40:50,248 --> 00:40:51,113
And when it does,
当这样的事发生了,

900
00:40:51,182 --> 00:40:54,083
that dictionary's going to have the information
那本字典会有信息

901
00:40:54,151 --> 00:40:57,453
related to that particular launch,
相关的特定的发射,

902
00:40:57,522 --> 00:40:59,722
Now I'm gonna warn you of something, when you're doing
现在我要警告你,当你做的事情

903
00:40:59,791 --> 00:41:01,757
your final project, you're gonna be searching on
你最后的项目,你要搜索

904
00:41:01,826 --> 00:41:03,826
the Internet all the time to find ways to do things,
所有的时间上网寻找方法,

905
00:41:03,895 --> 00:41:06,328
And you might run across really old posts, which you
你可能会遇到非常古老的帖子,你

906
00:41:06,397 --> 00:41:09,298
can often tell because they're in Objective C versus Swift,
通常可以告诉因为他们在Objective - C和迅速,

907
00:41:09,367 --> 00:41:11,934
But if you ever see a post where
但是如果你看到一个帖子

908
00:41:12,003 --> 00:41:15,704
someone in their application did finish launching with
有人在他们的应用程序并完成启动

909
00:41:15,773 --> 00:41:19,408
options is like saying UI split view controller init,
就好比说UI分割视图控制器初始化选项,

910
00:41:19,477 --> 00:41:21,344
or navigation init,
或导航初始化,

911
00:41:21,412 --> 00:41:24,247
And they're building their UI in code right there,
他们正在构建UI的代码,

912
00:41:24,316 --> 00:41:26,516
that's pre-story board code,
这是pre-story板代码,

913
00:41:26,585 --> 00:41:30,086
we do that stuff in the story board now,
我们现在做的东西在故事板,

914
00:41:30,154 --> 00:41:33,756
The times that we build any UI in application did finish
《纽约时报》,我们构建任何UI应用程序完成

915
00:41:33,825 --> 00:41:36,492
launching, 0,001% of the time,
启动,0001%的时间,

916
00:41:36,561 --> 00:41:41,263
So I just wanna make sure you don't get confused by that,
所以我只是想确保你不感到困惑,

917
00:41:41,332 --> 00:41:44,767
So this little delegate method is sent with that arrow
所以这个小箭头委托方法发送

918
00:41:44,836 --> 00:41:45,601
right there,
在这里,

919
00:41:45,670 --> 00:41:46,836
You see the arrow that's down there?
你看到下面的箭头吗?

920
00:41:46,904 --> 00:41:49,605
So that's the arrow where you go from not running
这是箭,你从没有运行

921
00:41:49,674 --> 00:41:51,307
into being inactive,
是不活跃的,

922
00:41:52,577 --> 00:41:54,043
So you're running, you can do stuff, but
所以你跑步,你可以做的东西,但是

923
00:41:54,111 --> 00:41:54,677
you're not on screen,
你不是在屏幕上,

924
00:41:54,746 --> 00:41:56,946
So in ApplicationDidFinishLaunching
所以在ApplicationDidFinishLaunching

925
00:41:57,015 --> 00:41:59,348
with options, you could be building your UI, but
选项,您可以构建UI,但是

926
00:41:59,417 --> 00:42:00,883
you can't put it on screen yet,
你不能把它放在屏幕上,

927
00:42:00,951 --> 00:42:02,017
I mean, it won't appear on screen
我的意思是,它不会出现在屏幕上

928
00:42:02,086 --> 00:42:03,119
cuz you're still inactive,
因为你还不活跃,

929
00:42:05,423 --> 00:42:08,123
Now I wanna talk briefly about an opposite
现在我想谈谈一个相反

930
00:42:08,192 --> 00:42:11,027
arrow there that can go into the inactive state,
箭头,可以进入不活动状态,

931
00:42:11,095 --> 00:42:12,962
You can get into inactive from running, but
您可以从运行进入不活动,但是

932
00:42:13,031 --> 00:42:15,498
you can also get inactive when you were running,
你也可以活动你跑步时,

933
00:42:19,737 --> 00:42:23,038
And things happen, like you switch to another app, other
像你这样的事情发生,切换到另一个应用程序,其他

934
00:42:23,107 --> 00:42:25,874
things can happen that cause you to go back to the inactive
事情会发生让你回到不活跃

935
00:42:25,943 --> 00:42:28,644
state, where you no longer can do UI,
状态,你不再能做UI,

936
00:42:28,713 --> 00:42:33,416
This transition, which is the WillResignActive transition,
这种转变,WillResignActive过渡,

937
00:42:33,485 --> 00:42:36,685
you want to think of that as the pause button,
你想暂停按钮,

938
00:42:36,754 --> 00:42:39,521
This is where your app wants to pause,
这就是你的应用要暂停,

939
00:42:39,590 --> 00:42:41,624
So if we were doing an asteroids app,
如果我们做一个小行星应用,

940
00:42:41,693 --> 00:42:44,760
I'd want to stop all of my asteroids,
我想要停止我所有的小行星,

941
00:42:44,829 --> 00:42:46,696
remember what their velocities were,
记住他们的速度,

942
00:42:47,966 --> 00:42:50,299
And be in a pause state,
处于暂停状态,

943
00:42:50,368 --> 00:42:51,833
And then I'll show you what I'm gonna
然后我会告诉你我要什么

944
00:42:51,902 --> 00:42:53,335
unpause in a second here,
unpause在第二个,

945
00:42:53,404 --> 00:42:54,203
Then bring it all back,
然后把它回来,

946
00:42:54,271 --> 00:42:56,605
So this is pause, I like to think of this one as pause,
这是暂停,我想这一停顿,

947
00:42:56,674 --> 00:42:59,108
you're going from being the active app where your UI's
你要从活动应用程序UI的

948
00:42:59,177 --> 00:43:00,609
working to this inactive state,
努力这种不活跃的状态,

949
00:43:00,678 --> 00:43:01,910
You're still in the foreground,
你仍然在前台,

950
00:43:01,979 --> 00:43:03,813
Now what causes this to happen?
是什么原因导致这种情况发生呢?

951
00:43:03,881 --> 00:43:06,615
A phone call comes in, when a phone call comes in,
一个电话进来,当一个电话进来,

952
00:43:06,684 --> 00:43:08,784
your app kind of is in the background,
你的应用程序在后台的,

953
00:43:08,853 --> 00:43:10,018
It's, you can't do any UI,
你不能做任何UI,

954
00:43:10,087 --> 00:43:12,922
it gets no events because the person's talking on the phone,
它没有事件,因为人的讲电话,

955
00:43:12,991 --> 00:43:14,356
But as soon as their phone call ends,
但一旦他们电话结束,

956
00:43:14,425 --> 00:43:15,925
you go back to being the active state,
你回到活动状态,

957
00:43:15,994 --> 00:43:17,360
you never went into the background,
你永远不会走进后台,

958
00:43:17,428 --> 00:43:18,828
You just were foreground inactive,
你只是前景不活跃,

959
00:43:21,599 --> 00:43:23,232
Or you'll pass through this arrow
或者你会经过这个箭头

960
00:43:23,301 --> 00:43:24,867
on your way to the background,
在你的背景,

961
00:43:24,936 --> 00:43:27,270
Someone did click on another app, and so
有人点击另一个应用程序,因此

962
00:43:27,338 --> 00:43:30,606
you're transitioning back here, still wanna pause,
你过渡回到这里,还想暂停,

963
00:43:30,675 --> 00:43:33,142
And then you're gonna go to the background, gonna clean up
然后你要去后台,要清理

964
00:43:33,211 --> 00:43:35,544
some more cuz you might get terminated later,
一些因为你可能会终止后,

965
00:43:35,613 --> 00:43:38,581
But here, you still, i's worth pausing as you pass
但在这里,你还在,我值得你通过暂停

966
00:43:38,650 --> 00:43:42,785
through here, so tha's what the resign state is,
在这里,所以那是辞职的状态是什么,

967
00:43:42,854 --> 00:43:44,754
This other arrow going in the other direction,
另一箭向着另一个方向,

968
00:43:44,823 --> 00:43:48,390
this is when your app really starts up,
这是当你的应用程序启动时,

969
00:43:48,459 --> 00:43:50,793
So this is when your UI is available,
这是当你的UI是可用的,

970
00:43:50,862 --> 00:43:53,796
Here's where you wanna unpause,
在这里你想unpause,

971
00:43:53,864 --> 00:43:57,166
If you have paused, then here's where you unpause,
如果你有停顿了一下,然后在这里你unpause,

972
00:43:57,235 --> 00:43:59,802
is in this DidBecomeActive,
在这个DidBecomeActive,

973
00:43:59,870 --> 00:44:02,505
Because you're gonna pass through this on your way back
因为你要通过这回来的路上

974
00:44:02,573 --> 00:44:05,241
from being in the background or when the phone call ends,
从背景中或在电话结束时,

975
00:44:05,310 --> 00:44:06,742
then you're gonna go active,
然后你要活跃,

976
00:44:06,811 --> 00:44:08,678
So this is the unpause,
这是unpause,

977
00:44:10,014 --> 00:44:12,848
Now you only unpause obviously if you're paused,
现在你只有unpause显然如果你停了下来,

978
00:44:12,917 --> 00:44:15,084
You never paused, then there's no unpause here,
你从不停顿了一下,然后这里没有unpause,

979
00:44:16,787 --> 00:44:18,186
This little arrow down in the corner,
这个小箭头在角落里,

980
00:44:18,255 --> 00:44:21,290
this is the DidEnterBackground state,
这是DidEnterBackground状态,

981
00:44:21,359 --> 00:44:23,759
this is where you wanna batten down the hatches,
这就是你想未雨绸缪,

982
00:44:23,828 --> 00:44:26,662
You wanna save any unsaved information,
你想保存任何未保存的信息,

983
00:44:26,731 --> 00:44:28,564
you've already paused probably,
你可能已经停了下来,

984
00:44:28,632 --> 00:44:32,235
because you went up through the active, can't get there
因为你通过主动上去,不能到达那里

985
00:44:32,303 --> 00:44:35,438
from active, unless you went through the inactive pause,
从活跃,除非你经历活动暂停,

986
00:44:35,507 --> 00:44:37,440
See how the arrows go there, so
看箭头去那里

987
00:44:37,508 --> 00:44:39,541
here's where you wanna save things,
在这里你要保存的东西,

988
00:44:39,610 --> 00:44:42,278
You wanna get yourself in the state, you got about 30
你想让自己的国家,你有大约30

989
00:44:42,347 --> 00:44:44,480
seconds to do it where you could be killed and
秒,你可以杀,

990
00:44:44,549 --> 00:44:46,782
usually would lose any data or anything,
通常将失去任何数据,

991
00:44:46,850 --> 00:44:49,351
This is also a good place maybe to
也许这也是一个好地方

992
00:44:49,420 --> 00:44:51,754
save your state a little bit, so if you did get killed and
保存你的状态一点,所以如果你做得到死亡,

993
00:44:51,823 --> 00:44:52,788
you got run again,
你有再次运行,

994
00:44:52,857 --> 00:44:55,291
you could start up exactly where you were,
你可以启动你是哪里,

995
00:44:55,360 --> 00:44:57,493
And there's actually certain infrastructure in
和有一定的基础设施

996
00:44:57,562 --> 00:44:59,728
UI application, which I'll mention in a second,
UI应用程序,我将提到,

997
00:44:59,797 --> 00:45:00,762
to do that,
要做到这一点,

998
00:45:00,831 --> 00:45:04,567
So this is the batten down the hatches area right here,
这是未雨绸缪的区域,

999
00:45:04,635 --> 00:45:06,135
the transition,
的转变,

1000
00:45:06,203 --> 00:45:09,538
When you come back out of the background, so
当你回来的背景,所以

1001
00:45:09,607 --> 00:45:11,407
you were in the background or
你是在后台

1002
00:45:11,475 --> 00:45:15,844
suspended, when you come back out, you're gonna get this
暂停了,当你回来,你会得到这个

1003
00:45:15,913 --> 00:45:19,115
ApplicationWillEnterForegro- und,
ApplicationWillEnterForegro - und,

1004
00:45:19,183 --> 00:45:22,718
So, that's the thing that says, you will, back up,
这是说的东西,你会回来,

1005
00:45:22,787 --> 00:45:25,788
this is where you can unbatten down the hatches if you
在这里你可以unbatten如果你做准备

1006
00:45:25,856 --> 00:45:28,290
wanna open some files that you had closed or
想要一些文件,你已经关闭或打开

1007
00:45:28,359 --> 00:45:30,859
something like that, you can do that here,
这样,你可以在这里,

1008
00:45:30,928 --> 00:45:32,227
Have you got that?
你明白我的意思吗?

1009
00:45:32,296 --> 00:45:35,364
So these are the transitions you make through the lifetime
这是转换你一生

1010
00:45:35,433 --> 00:45:36,732
of your application,
你的应用程序中,

1011
00:45:36,801 --> 00:45:39,802
The ApplicationDelegate is involved in a lot of other
ApplicationDelegate参与很多其他的

1012
00:45:39,871 --> 00:45:41,970
things as well besides just the lifecycle,
东西除了生命周期,

1013
00:45:42,039 --> 00:45:44,506
For example, state restoration, this is the thing
例如,状态恢复,这是一件事

1014
00:45:44,575 --> 00:45:47,242
I was telling you be, just moments ago, where you can
我告诉你,就在片刻前,你可以

1015
00:45:47,311 --> 00:45:49,578
save your state, so that when you launch again, yo're in
拯救你的国家,所以,当你再次启动,哟

1016
00:45:49,647 --> 00:45:52,114
exactly the same state on the same view controller,
完全相同的状态在同一视图控制器,

1017
00:45:52,183 --> 00:45:55,785
Maybe even your first responder is the same blinking
甚至你的第一反应都是一样的闪烁

1018
00:45:55,853 --> 00:45:57,319
cursor and the same text field or whatever,
光标和相同的文本字段,

1019
00:45:57,388 --> 00:45:59,054
you can save all that, there's a whole mechanism for
你可以保存所有,有一个完整的机制

1020
00:45:59,123 --> 00:45:59,688
doing that,
这样做,

1021
00:45:59,757 --> 00:46:01,323
You can take a look at it if you want,
你可以看看它如果你想,

1022
00:46:01,392 --> 00:46:04,326
might be a good thing to get a rubric point out of in there,
可能是一件好事的标题指出,

1023
00:46:04,395 --> 00:46:08,030
Also data protection, so the data on your phone
数据保护,数据在你的手机上

1024
00:46:08,098 --> 00:46:12,535
is protected by default when you're in the locked state,
默认情况下保护处于锁定状态时,

1025
00:46:12,603 --> 00:46:14,303
Your phone is locked,
你的手机被锁定,

1026
00:46:14,372 --> 00:46:16,972
Then all the phone, data on it is encrypted, so
然后所有的电话,数据是加密的,因此

1027
00:46:17,041 --> 00:46:19,642
even if someone broke into the phone somehow and
即使有人闯入了电话不知怎么的和

1028
00:46:19,710 --> 00:46:21,610
got the data out of the static ram,
有静态ram的数据,

1029
00:46:21,679 --> 00:46:24,113
It would all be encrypted, so it'll be useless anyway,
这都是加密的,所以它会是无用的,

1030
00:46:24,182 --> 00:46:25,848
So the AppDelegate can tell you when
所以在AppDelegate可以告诉你什么时候

1031
00:46:25,917 --> 00:46:28,317
data becomes unencrypted and available for use,
数据加密和可供使用,

1032
00:46:28,385 --> 00:46:31,387
In other words, unlock, the screen has been unlocked, or
换句话说,解锁,解锁屏幕,或

1033
00:46:31,455 --> 00:46:33,156
when it goes back to being locked,
当它回到被锁,

1034
00:46:34,925 --> 00:46:37,759
You can open URLs in other apps,
你可以打开网址在其他应用程序,

1035
00:46:37,828 --> 00:46:40,362
There's a method, I think you wanted the extra credit items,
有一个方法,我认为你想要额外的信贷项目,

1036
00:46:40,431 --> 00:46:41,430
Or maybe we've even made it as
也许我们甚至使它

1037
00:46:41,499 --> 00:46:43,298
part of the required task of one,
必需的任务的一部分,

1038
00:46:43,367 --> 00:46:44,767
So you probably know how to do that,
所以你可能知道怎么做,

1039
00:46:45,836 --> 00:46:46,635
This is the other way around,
这是相反的,

1040
00:46:46,704 --> 00:46:52,141
This is someone's asking you to open a URL in AppDelegate,
这是别人问你在AppDelegate开设一个URL,

1041
00:46:52,210 --> 00:46:53,708
So this is: you'll get this message,
这是:你会得到这条消息,

1042
00:46:53,777 --> 00:46:56,245
your AppDelegate saying, hey, this, some other app wants you
你AppDelegate说,嘿,这一点,其他应用程序希望你

1043
00:46:56,314 --> 00:46:58,413
to open this URL, and you can go do it,
打开这个网址,你可以去做,

1044
00:46:58,482 --> 00:46:59,782
Similar to if you got launched,
如果你有类似启动,

1045
00:46:59,850 --> 00:47:01,283
if you didn't get launched to it,
如果你没有得到了它,

1046
00:47:01,351 --> 00:47:02,751
because if you got launched to it,
因为如果你有了它,

1047
00:47:02,820 --> 00:47:04,987
it's gonna be in that dictionary, but otherwise,
它会在那本字典,但除此之外,

1048
00:47:05,056 --> 00:47:06,755
you'll get this method,
你会得到这个方法,

1049
00:47:06,824 --> 00:47:08,523
And there's also a whole mechanism for
还有一个机制

1050
00:47:08,592 --> 00:47:09,992
background fetching,
背景提取,

1051
00:47:10,061 --> 00:47:12,661
Sometimes you might have an app, it's a social media app,
有时你可能有一个应用程序,这是一个社会媒体应用,

1052
00:47:12,730 --> 00:47:14,996
And you wanna have up to date information for
和你想要的最新信息

1053
00:47:15,065 --> 00:47:18,300
the user at all times, so that if they launch, they're seeing
用户在任何时候,如果他们发射,看

1054
00:47:18,369 --> 00:47:21,637
the latest posts on your Facebook page, or whatever,
最新的文章在你的Facebook页面上,等等,

1055
00:47:21,705 --> 00:47:24,373
And to do that, you can set up this background fetching,
为此,您可以设置这个后台取回,

1056
00:47:24,442 --> 00:47:26,742
Now, the background fetching is not happening once a minute
现在,后台抓取一分钟没有发生一次

1057
00:47:26,810 --> 00:47:27,542
or anything like that,
或类似的东西,

1058
00:47:27,611 --> 00:47:28,944
It's happening, you know,
它发生,你知道,

1059
00:47:29,013 --> 00:47:30,612
occasionally in the background, and
偶尔在后台,

1060
00:47:30,681 --> 00:47:32,981
if you try to do too much, the system,
如果你试图做太多,系统,

1061
00:47:33,050 --> 00:47:35,985
will get upset at you and stop doing, scheduling you so much,
会难过在你停止做,安排你,

1062
00:47:36,053 --> 00:47:39,254
But what happens here in the background fetching is, you
但是这里发生了什么在后台抓取,你

1063
00:47:39,323 --> 00:47:42,658
move from the suspended state into the background state for
从挂起状态到背景状态

1064
00:47:42,727 --> 00:47:44,559
30 seconds or less, usually,
30秒或更少,通常,

1065
00:47:44,628 --> 00:47:46,695
And you go you get to go fetch on the network or
和你走在网络或去取回

1066
00:47:46,764 --> 00:47:48,130
get your latest information, and
把你的最新信息

1067
00:47:48,199 --> 00:47:50,166
then you go back to suspended,
然后你回到暂停,

1068
00:47:50,234 --> 00:47:52,034
So that way if you go suspended background,
所以,如果你暂停了背景,

1069
00:47:52,103 --> 00:47:54,804
foreground active really quick, you got the data,
前台主动很快,你得到数据,

1070
00:47:57,541 --> 00:48:00,542
There's a few other things, but that's mostly what
有一些其他的事情,但那是什么

1071
00:48:00,611 --> 00:48:03,179
the ApplicationDelegate is all about,
ApplicationDelegate就是,

1072
00:48:03,247 --> 00:48:06,415
Now application delegate of course has to be a delegate
现在应用程序委托当然必须是一个委托

1073
00:48:06,483 --> 00:48:07,349
of some object,
的对象,

1074
00:48:07,418 --> 00:48:09,985
And it's a delegate of UI application,
这是一个UI应用程序的委托,

1075
00:48:10,054 --> 00:48:12,788
So UI application is a class there's only a single instance
所以UI应用程序是一个类只有一个实例

1076
00:48:12,857 --> 00:48:14,557
that you ever have in your app,
你曾经在你的应用程序,

1077
00:48:14,625 --> 00:48:17,526
You get it by saying UIApplication,shared and
你得到UIApplication说,和共享

1078
00:48:17,594 --> 00:48:20,296
it manages all the global behavior,
它管理的全球行为,

1079
00:48:20,364 --> 00:48:22,898
Which sounds like, wow this is really important object,
这听起来像,哇,这是非常重要的对象,

1080
00:48:22,967 --> 00:48:24,233
But actually it's not that important,
但实际上并不是那么重要,

1081
00:48:24,301 --> 00:48:27,369
You almost never interact with UIApplication, because it
你几乎从不UIApplication相互作用,因为它

1082
00:48:27,438 --> 00:48:31,240
delegates all the interesting things to its app delegates,
代表应用程序代表,所有的有趣的事情

1083
00:48:31,309 --> 00:48:33,442
But there are a few things that you can do in
但有几件事你可以做

1084
00:48:33,511 --> 00:48:34,543
UIApplication,
UIApplication,

1085
00:48:34,612 --> 00:48:39,281
For example, here's where you can open URL in another app
例如,你可以在另一个应用程序打开URL

1086
00:48:39,350 --> 00:48:42,384
you can register to receive push notifications here,
你可以在这里注册接收推送通知,

1087
00:48:42,453 --> 00:48:44,954
Push notifications your app will not get
推送通知应用程序将不会得到

1088
00:48:45,022 --> 00:48:48,090
unless you call this registerForRemoteNotifications
除非你称之为registerForRemoteNotifications

1089
00:48:48,159 --> 00:48:49,157
in UIApplication,
UIApplication在,

1090
00:48:49,226 --> 00:48:51,994
By the way, notifications, push notifications and
顺便说一下,通知,推送通知

1091
00:48:52,063 --> 00:48:56,398
local notifications have been unified in iOS 10 to this UN
当地通知联合国统一在iOS 10

1092
00:48:56,467 --> 00:48:58,433
notifications framework,
通知框架,

1093
00:48:58,502 --> 00:49:01,103
A local notification, a push notification you probably know
本地通知推送式通知你可能知道

1094
00:49:01,171 --> 00:49:03,238
what this is that's when some server send you
这是什么这是当某些服务器发送你

1095
00:49:03,307 --> 00:49:05,707
some information like in the cloud kit case where it's
一些信息像云中的装备情况

1096
00:49:05,776 --> 00:49:08,443
telling you hey some data changed in your data base,
告诉你嗨一些数据改变了在你的数据库,

1097
00:49:08,512 --> 00:49:11,313
But local notification are kind of cool as well,
但当地通知也挺酷的,

1098
00:49:11,381 --> 00:49:13,783
You can set up local notification that will fire at
您可以设置本地通知开火

1099
00:49:13,851 --> 00:49:14,583
a certain time,
一个特定的时间,

1100
00:49:14,652 --> 00:49:18,253
That's how a calendar app reminds you when you have
这是一个日历应用程序提醒你当你有

1101
00:49:18,322 --> 00:49:22,090
a particular appointment or rather it's using local
一个特定的约会或者使用本地

1102
00:49:22,159 --> 00:49:26,195
notifications and you schedule them for a certain time,
通知你安排一定的时间,

1103
00:49:26,263 --> 00:49:29,531
I think you can also do local notifications for location
我认为你也可以做局部地点的通知

1104
00:49:29,600 --> 00:49:33,435
changes, and you get near the dry cleaner or whatever,
变化,得到附近的干洗店之类的,

1105
00:49:33,504 --> 00:49:35,704
So local notifications,
所以当地的通知,

1106
00:49:35,773 --> 00:49:37,973
put push notifications are unified in iOS 10 and
将统一在iOS 10和推送通知

1107
00:49:38,041 --> 00:49:40,910
it's not part of UIApplication it's this other framework,
这不是UIApplication的其他框架的一部分,

1108
00:49:42,713 --> 00:49:44,613
Unfortunately I didn't have time to go over that,
不幸的是我没有时间复习,

1109
00:49:44,682 --> 00:49:47,215
By the way also local notifications is different
顺便也当地通知是不同的

1110
00:49:47,284 --> 00:49:49,985
from NSnotification, or just notification,
从NSnotification,或者只是通知,

1111
00:49:50,054 --> 00:49:52,320
Notification is that radio station thing,
通知是电台的事情,

1112
00:49:52,389 --> 00:49:55,457
local notification, and push notification are the, this
当地通知,和推送通知

1113
00:49:55,525 --> 00:49:58,460
other mechanism for notifying the user which is actually
实际上其他机制来通知用户

1114
00:49:58,529 --> 00:50:01,430
completely different not related to each other at all,
完全不同与彼此无关,

1115
00:50:03,334 --> 00:50:06,702
In application you can also set the fetching interval for
在应用程序还可以设置抓取区间

1116
00:50:06,771 --> 00:50:09,638
that background fetching thing I talked about,
这一背景下抓取东西我谈到,

1117
00:50:09,706 --> 00:50:12,274
If you get into the background and
如果你进入后台

1118
00:50:12,343 --> 00:50:16,611
you need more time, because 30 seconds is not enough,
你需要更多的时间,因为30秒是不够的,

1119
00:50:16,680 --> 00:50:19,949
Something is blocking or you need to get something from
什么是阻止或者需要得到一些东西

1120
00:50:20,018 --> 00:50:21,616
the network and you want some more time,
网络,你想要一些更多的时间,

1121
00:50:21,685 --> 00:50:24,753
You can ask for more time by asking the UI application
你可以要求更多的时间通过询问UI应用程序

1122
00:50:24,821 --> 00:50:27,456
object to begin a background task,
对象开始一个后台任务,

1123
00:50:27,524 --> 00:50:29,258
Now, again, you can't abuse this,
现在,你不能滥用,

1124
00:50:29,327 --> 00:50:31,293
If you keep asking for more and more time, and
如果你继续要求更多和更多的时间,和

1125
00:50:31,362 --> 00:50:32,628
you're trying to run for ten minutes,
你想跑了十分钟,

1126
00:50:32,696 --> 00:50:35,898
eventually the system's gonna say, that's enough,
最终系统的会说,这就够了,

1127
00:50:35,966 --> 00:50:38,533
This is for, just exceptional circumstances where,
这是特殊情况,

1128
00:50:38,602 --> 00:50:40,468
"argh, I need another minute please",
“啊,我需要一分钟请”,

1129
00:50:40,537 --> 00:50:42,238
Can I have some more time?
我可以有更多的时间吗?

1130
00:50:42,306 --> 00:50:44,807
And it'll give it to you as long as you don't abuse it,
它会给你只要你不滥用它,

1131
00:50:46,510 --> 00:50:49,678
The little spinner in the upper left hand corner of your
的小转轮的左上角

1132
00:50:49,747 --> 00:50:51,647
device, okay, that spins,
好的设备,旋转,

1133
00:50:51,715 --> 00:50:53,314
Have you ever seen that thing spinning when you're doing
你见过那个东西旋转,当你在做什么

1134
00:50:53,383 --> 00:50:54,550
something on the network?
网络上的东西吗?

1135
00:50:54,618 --> 00:50:56,418
You can control that, you can turn it on and
你可以控制,你可以打开它

1136
00:50:56,487 --> 00:50:59,921
off with this bool in UIApplication,
UIApplication这bool,

1137
00:50:59,990 --> 00:51:02,324
You can also find out a lot of information like remember that
你也可以找到很多信息就像记住

1138
00:51:02,392 --> 00:51:05,928
category sizer, the little slider text size slider,
类别筛选器,小滑块滑块文字大小,

1139
00:51:05,996 --> 00:51:07,963
You can find out what the preferred content slide
您可以找出首选内容

1140
00:51:08,031 --> 00:51:09,931
category currently is,
类别目前,

1141
00:51:10,000 --> 00:51:12,067
You can find out how much time you got remaining
你可以找到你剩下多少时间

1142
00:51:12,136 --> 00:51:14,803
on your background, sitting in the background,
在你的背景,坐在后台,

1143
00:51:14,872 --> 00:51:16,372
You can also find which state you're in,
你还可以找到哪个州你在,

1144
00:51:16,440 --> 00:51:19,341
foreground inactive, foreground active background,
前景前景不活跃,活跃的背景下,

1145
00:51:19,409 --> 00:51:21,210
You can find out which of those states you're in,
你可以找到哪些州你在,

1146
00:51:21,278 --> 00:51:22,878
So you're application's a little bit of a clearing
所以你应用程序的一点点的清理

1147
00:51:22,947 --> 00:51:24,313
house for that kind of global information,
房子的全球信息,

1148
00:51:26,083 --> 00:51:27,516
So that's it for UIApplication,
UIApplication就是这样的,

1149
00:51:27,585 --> 00:51:31,654
Info,plist, we've already seen Info,plist,
plist信息,我们已经看到信息,plist,

1150
00:51:31,722 --> 00:51:36,291
Info,plist is really like a raw data file that's storing
信息,plist是真的喜欢原始数据文件的存储

1151
00:51:36,360 --> 00:51:39,228
a lot of your application's settings,
很多应用程序的设置,

1152
00:51:39,297 --> 00:51:43,032
We saw the one where we had HTTP URLs and
我们看到了一个HTTP url和

1153
00:51:43,101 --> 00:51:45,267
we want it to allow those unsecure ones,
我们想要让那些不安全的,

1154
00:51:45,336 --> 00:51:47,769
remember that the app transport security,
记住,应用交通安全,

1155
00:51:47,838 --> 00:51:51,807
We actually went and edited our Info,plist,
我们实际上和编辑信息,plist,

1156
00:51:51,876 --> 00:51:54,609
You can see it looks like this when you click on it,
你可以看到它是这样,当你点击它,

1157
00:51:54,678 --> 00:51:56,778
This is a property list editor right here,
这是一个属性列表编辑器,

1158
00:51:56,847 --> 00:51:59,147
So on the left hand side you're gonna have strings and
所以,在左手边你会有字符串和

1159
00:51:59,216 --> 00:52:01,383
dictionaries and arrays,
词典和数组,

1160
00:52:01,452 --> 00:52:03,052
Things that property lists are allowed to have,
属性列表允许的事情,

1161
00:52:03,120 --> 00:52:04,152
And on the right you're gonna have
右边你会有

1162
00:52:04,221 --> 00:52:05,554
the values that are in there,
的值,

1163
00:52:05,622 --> 00:52:08,257
This is really backing an XML file,
这真的是一个XML文件支持,

1164
00:52:08,325 --> 00:52:10,358
this property list that stores an XML file,
这个属性列表存储XML文件,

1165
00:52:10,427 --> 00:52:12,928
You can actually right-click on it and
你可以右键点击它

1166
00:52:12,997 --> 00:52:14,763
edit it as an XML file,
编辑XML文件,

1167
00:52:14,832 --> 00:52:17,465
I strongly recommend against this because
我强烈建议反对这样做,因为

1168
00:52:17,534 --> 00:52:19,134
you can break this so easily,
你可以轻易打破这种,

1169
00:52:19,203 --> 00:52:22,104
And then now the app won't be able to read this info,plist
然后现在应用程序无法读取信息,plist

1170
00:52:22,172 --> 00:52:25,440
anymore, so I recommend against doing that,
了,所以我不建议这样做,

1171
00:52:25,509 --> 00:52:27,276
But usually all these settings,
但通常这些设置,

1172
00:52:27,344 --> 00:52:30,913
you edit them in the project settings, right,
你编辑的项目设置,

1173
00:52:30,981 --> 00:52:33,015
You're not going to the Info,plist,
你不会信息,plist,

1174
00:52:33,083 --> 00:52:34,583
But it doesn't happen to be one or
但它不会发生一个或

1175
00:52:34,652 --> 00:52:37,485
at least I've never found one for that app transport
至少我从来没有发现一个用于应用程序传输

1176
00:52:37,554 --> 00:52:40,555
security, but maybe they want it intentionally obscure
安全,但也许他们想要故意模糊

1177
00:52:40,624 --> 00:52:43,792
because they want your app to be secure in that way,
因为他们想让你的应用程序是安全的,

1178
00:52:43,861 --> 00:52:45,995
But you've seen many, many settings here,
但是你看过很多设置,

1179
00:52:46,063 --> 00:52:48,497
like do we allow a portrait upside down, and
像我们允许肖像颠倒,

1180
00:52:48,566 --> 00:52:52,935
things like that, these are all stored in the Info,plist,
类似这样的事情,这些都是存储在信息,plist,

1181
00:52:53,004 --> 00:52:56,805
So this settings UI that you see is pretty much
这设置界面,你看到的是差不多

1182
00:52:56,874 --> 00:52:59,308
an editor also on Info,plist for
同样在信息,编辑plist

1183
00:52:59,377 --> 00:53:01,143
a lot of the things that you see there,
你看到的很多东西,

1184
00:53:03,180 --> 00:53:05,681
Another thing that you'll see in your settings
另一件事,你将看到在你的设置

1185
00:53:05,750 --> 00:53:07,616
are capabilities,
功能,

1186
00:53:07,685 --> 00:53:09,785
They're a number of features,
他们的特性,

1187
00:53:09,854 --> 00:53:14,489
couple dozen maybe, that require an external server,
几个可能,需要一个外部服务器,

1188
00:53:14,558 --> 00:53:17,025
Some external resource like iCloud or
像iCloud和一些外部资源

1189
00:53:17,094 --> 00:53:20,061
like CloudKit, requires some server that's storing all that
像CloudKit一样,需要一些服务器的存储

1190
00:53:20,130 --> 00:53:21,930
data out there or Game Center,
数据或游戏中心,

1191
00:53:21,999 --> 00:53:25,200
Is has all the servers so people can get together and
是所有服务器已经使人们可以聚在一起吗

1192
00:53:25,269 --> 00:53:27,068
play games and things like that,
玩游戏之类的,

1193
00:53:27,137 --> 00:53:31,073
When you have that kind of thing where you essentially
当你有这样的事情,你

1194
00:53:31,142 --> 00:53:33,308
need your app to be authenticated so
需要你的应用验证

1195
00:53:33,377 --> 00:53:37,646
that it it the server you're talking to knows it's you,
它的服务器你说知道是你,

1196
00:53:37,715 --> 00:53:40,649
Then you're going to have to go to the capabilities tab in
然后你要去的功能选项卡

1197
00:53:40,718 --> 00:53:43,619
the project settings and turn it on,
项目设置,打开它,

1198
00:53:43,687 --> 00:53:47,222
And turning it on, basically means update my entitlements
并把它,基本上意味着更新我的权利

1199
00:53:47,290 --> 00:53:50,926
so that I'm entitled to do this particular thing,
所以我有权做这个事情,

1200
00:53:50,994 --> 00:53:53,529
So, see some of the examples up there besides iCloud and
所以,看到一些例子除了iCloud和

1201
00:53:53,597 --> 00:53:56,064
Game Center at the top, you have Apple Pay,
游戏中心顶部,苹果支付,

1202
00:53:56,132 --> 00:54:00,569
In App Purchases, obviously these things require servers
在应用程序购买,显然这些事情需要服务器

1203
00:54:00,638 --> 00:54:02,303
and people connecting to them and things,
和人们连接到他们的事情,

1204
00:54:02,372 --> 00:54:04,405
Even the background fetching modes and
甚至和后台抓取模式

1205
00:54:04,474 --> 00:54:08,643
things like that require some entitlement if you're gonna be
比如,如果你要,需要一些权利

1206
00:54:08,712 --> 00:54:11,179
doing fetching while in the background,
在后台做抓取时,

1207
00:54:11,248 --> 00:54:13,882
So, check these out, this is a cool thing just to see what
所以,看看这些,这仅仅是一件很酷的事情,看看

1208
00:54:13,951 --> 00:54:15,350
features there are out there,
功能有,

1209
00:54:15,419 --> 00:54:17,653
Again, maybe way to get add some breadth,
再次,也许方法添加一些宽度,

1210
00:54:17,721 --> 00:54:20,922
some of them are not that difficult to implement,
他们中的一些人并不那么难以实现,

1211
00:54:20,991 --> 00:54:23,225
simple versions of anyway,
简单的版本,

1212
00:54:23,294 --> 00:54:27,396
But, you have to turn these on just to enable them,
但是,你必须把这些使他们,

1213
00:54:30,735 --> 00:54:34,169
My last topic here today is persistence,
今天我最后一次主题是坚持,

1214
00:54:34,238 --> 00:54:37,839
So persistence just means making data stay on the disk
所以持久性就意味着保持磁盘上的数据

1215
00:54:37,908 --> 00:54:40,775
when after your app is killed or dies,
当应用程序被杀或死后,

1216
00:54:40,844 --> 00:54:43,345
You already know about two really important ones,
你已经知道两个非常重要的,

1217
00:54:43,413 --> 00:54:47,048
User defaults which is tiny little pieces of data,
用户默认这是小块的数据,

1218
00:54:47,117 --> 00:54:49,518
preferences kind of data,
偏好类型的数据,

1219
00:54:49,587 --> 00:54:51,253
And has to be in PropertyLIst format,
并在PropertyLIst格式,

1220
00:54:51,322 --> 00:54:54,523
And then there's Core Data, which is kind of the opposite,
然后还有核心数据,这是相反的,

1221
00:54:54,591 --> 00:54:59,928
Monster relational database can have huge data in there,
怪物关系数据库可以有巨大的数据,

1222
00:54:59,996 --> 00:55:02,264
It's really for a data centric applications,
真的是对于以数据为中心的应用程序,

1223
00:55:02,332 --> 00:55:04,733
applications where the data is what is all about,
应用程序的数据是什么,

1224
00:55:04,802 --> 00:55:05,734
So, I'm not gonna talk about those,
所以,我不会谈论这些,

1225
00:55:05,802 --> 00:55:06,902
You know about those,
你知道这些,

1226
00:55:06,970 --> 00:55:09,204
I'm going to talk about these last three briefly,
我要去年三个简要谈论这些,

1227
00:55:09,272 --> 00:55:10,472
Archiving,
存档、

1228
00:55:10,541 --> 00:55:15,043
So archiving is a way of storing an object graph that
所以归档存储一个对象图的一种方式

1229
00:55:15,112 --> 00:55:17,813
is not a property list on disk,
不是一个磁盘上的属性列表,

1230
00:55:17,882 --> 00:55:20,815
Your storyboard is archived,
你的故事板存档,

1231
00:55:20,884 --> 00:55:23,418
Take all those views archives them to disk,
把所有那些观点档案到磁盘,

1232
00:55:23,487 --> 00:55:24,853
So, I talked about that,
所以,我讲过,

1233
00:55:24,922 --> 00:55:27,789
SQLite, we all know what SQL is,
SQLite,我们都知道SQL是什么,

1234
00:55:27,858 --> 00:55:29,991
its relation on database technology,
对数据库技术的关系,

1235
00:55:30,060 --> 00:55:35,563
iOS comes with kind of a light version of SQL at which
iOS带有一种光的版本的SQL

1236
00:55:35,632 --> 00:55:37,632
you don't usually ever use cuz you're using Core Data,
你通常不使用因为你使用核心数据,

1237
00:55:37,701 --> 00:55:41,269
Core Data's actually built on top of SQLite which
核心数据之上的SQLite

1238
00:55:41,338 --> 00:55:43,438
you don't have to access SQL directly,
你不需要直接访问SQL,

1239
00:55:43,507 --> 00:55:45,373
And finally, you can make things persist by
最后,你可以坚持的东西

1240
00:55:45,442 --> 00:55:47,609
putting them in the Unix file system,
让他们在Unix文件系统,

1241
00:55:47,678 --> 00:55:49,510
iOS, put Unix underneath, so
iOS,Unix下

1242
00:55:49,579 --> 00:55:52,480
you can put things in that file system,
你可以把东西放在文件系统,

1243
00:55:52,549 --> 00:55:54,482
We'll talk about how to do that,
我们将谈论如何做,

1244
00:55:54,551 --> 00:55:56,585
So, let's talk about archiving thing,
所以,让我们来谈谈存档,

1245
00:55:56,654 --> 00:56:01,389
Do not get the idea that this is a good way to
不懂的,这是一个好方法

1246
00:56:01,458 --> 00:56:03,959
have an arbitrary object graph that you have, and
你有任意对象图,

1247
00:56:04,028 --> 00:56:05,460
store it on disc,
存储盘,

1248
00:56:05,529 --> 00:56:08,764
Because archiving requires the involvement
因为归档要求参与

1249
00:56:08,832 --> 00:56:11,867
of all the objects that want to be archived,
所有的对象,想要存档,

1250
00:56:11,935 --> 00:56:15,203
Each of them has to implement these two methods up here
每个人都必须实现这两个方法

1251
00:56:15,272 --> 00:56:19,741
in code which essentially takes your object and
在本质上需要你的对象和代码

1252
00:56:19,810 --> 00:56:21,377
converts it into a dictionary,
将它转换成一个词典,

1253
00:56:22,746 --> 00:56:26,247
Not quite that, but that's 90% of what it is,
不,但这是90%的,

1254
00:56:26,316 --> 00:56:27,516
So converts to dictionary,
所以转换字典,

1255
00:56:27,585 --> 00:56:30,051
And then it also has to implement this initializer,
然后它还必须实现这个初始化,

1256
00:56:30,120 --> 00:56:32,020
any object that wants to be archived has to implement
任何对象,想要存档必须实现

1257
00:56:32,089 --> 00:56:32,954
this initializer,
这个初始化,

1258
00:56:33,023 --> 00:56:35,490
Which essentially gives you back that dictionary and
这给字典和你回来吗

1259
00:56:35,559 --> 00:56:38,293
tells you to create your objects from it,
告诉您创建对象,

1260
00:56:38,362 --> 00:56:41,229
Now this is kind of special,
这是特殊的,

1261
00:56:41,298 --> 00:56:44,599
this mechanism because the system is smart enough to
这种机制,因为系统足够聪明

1262
00:56:44,668 --> 00:56:47,802
know when you put an object in your dictionary,
知道当你把一个对象在你的字典,

1263
00:56:47,871 --> 00:56:50,539
And someone else in the same object graph
和别人在同一对象图

1264
00:56:50,608 --> 00:56:53,575
puts that object in there if that's the same object,
将该对象如果是同一个对象,

1265
00:56:53,643 --> 00:56:56,345
So it's not gonna ask that object to reconstitute itself
所以它不会要求对象重组本身

1266
00:56:56,413 --> 00:56:58,179
twice it's only gonna ask to do it once and
它只要求做一次两次

1267
00:56:58,248 --> 00:57:00,882
then it's gonna make pointers to it,
那么它会使指针,

1268
00:57:00,951 --> 00:57:03,651
So this is how the storyboard can work, if you think about
这就是故事板可以工作,如果你想

1269
00:57:03,720 --> 00:57:05,787
the storyboard, it's got a view hierarchy,
故事板,它有一个视图层次结构,

1270
00:57:05,856 --> 00:57:08,356
All those views are pointing to other views in their
所有这些观点是指向其他视图的

1271
00:57:08,425 --> 00:57:09,224
subviews but
子视图,但

1272
00:57:09,293 --> 00:57:11,893
they're also pointing back to their superviews,
他们也指出回到他们的父视图,

1273
00:57:11,962 --> 00:57:15,063
And obviously you only want one copy of every view in
很明显,你只想要一份每个视图

1274
00:57:15,131 --> 00:57:16,231
that hierarchy,
层次结构,

1275
00:57:16,299 --> 00:57:20,768
So UI view implements this coding protocol that has this
所以这个用户界面视图实现这个编码协议

1276
00:57:20,837 --> 00:57:22,004
methods in it,
方法,

1277
00:57:22,072 --> 00:57:25,240
And that's why view can be archived and all the sub cost
这就是为什么视图可以存档,所有子成本

1278
00:57:25,308 --> 00:57:27,709
of UI view that come with iOS like label and
的用户界面视图,像标签和iOS

1279
00:57:27,778 --> 00:57:29,777
button they also implement this,
他们也实现这个按钮,

1280
00:57:29,846 --> 00:57:32,780
And that's why the storyboard could be archived,
这就是为什么故事板可以存档,

1281
00:57:32,849 --> 00:57:37,552
But in the end if you start having an arbitrary
但到最后如果你开始拥有一个任意的

1282
00:57:37,621 --> 00:57:39,071
you try to implement this in code and UI for all of thems,
你想在代码中实现这个和UI主题,

1283
00:57:39,072 --> 00:57:40,522
object graph, and
对象图,

1284
00:57:40,591 --> 00:57:43,692
It starts to be more work than for example, just
例如,它开始被更多的工作比而已

1285
00:57:43,760 --> 00:57:47,996
making a core data database, to store that data in,
核心数据的数据库,存储数据,

1286
00:57:48,065 --> 00:57:50,432
Or converting it to a property list and
或将它转换为一个属性列表

1287
00:57:50,501 --> 00:57:52,401
using user defaults if it's a small thing,
使用用户违约,如果它是一个小的事情,

1288
00:57:54,604 --> 00:57:57,072
So this people here listen and they're like, that's cool,
这人听,他们就像,很酷,

1289
00:57:57,140 --> 00:57:59,674
yeah I've got a big object graph of data and
是的我有一个巨大的数据和对象图

1290
00:57:59,743 --> 00:58:01,643
I'm just gonna put it on this using this,
我要把它放在这用这个,

1291
00:58:01,712 --> 00:58:05,680
Well it's a little more involved than you might think,
这是更比你想象的,

1292
00:58:05,749 --> 00:58:08,416
And it also, you have to know what you're doing here to make
同时,你必须知道你在做什么在这里

1293
00:58:08,485 --> 00:58:11,386
sure you get those back pointers properly set up and
确保你拿回这些指针正确设置和

1294
00:58:11,455 --> 00:58:12,154
things like that,
类似这样的事情,

1295
00:58:14,425 --> 00:58:17,892
SQLite, so this is SQL in a single file,
SQLite,所以这是一个SQL文件,

1296
00:58:17,961 --> 00:58:20,962
one gigantic file the entire SQL database,
一个巨大的文件整个SQL数据库,

1297
00:58:21,030 --> 00:58:24,299
It's not a network thing it's purely just a local file,
它不是一个网络的事情纯粹只是一个本地文件,

1298
00:58:24,368 --> 00:58:28,570
SQLite is an Open Source project, comes with iOS,
SQLite是一个开源项目,iOS,

1299
00:58:28,639 --> 00:58:29,904
It's not really good for everything,
这不是很好的,

1300
00:58:29,973 --> 00:58:31,839
I wouldn't store huge things in there,
我不会储存巨大的事情,

1301
00:58:31,908 --> 00:58:32,740
It's not really built for
这不是真的了

1302
00:58:32,809 --> 00:58:36,044
that I'll probably put huge things in the file system,
我可能会把巨大的东西在文件系统中,

1303
00:58:36,112 --> 00:58:38,980
Even core data when you create something big like
当你创造一些大甚至核心数据

1304
00:58:39,049 --> 00:58:41,649
attribute NSData there's a switch in there,
属性NSData有一个开关,

1305
00:58:41,718 --> 00:58:44,552
You can turn on which is store this in the external file not
您可以打开存储在外部文件

1306
00:58:44,621 --> 00:58:46,354
actually in the data base,
实际的数据基础,

1307
00:58:46,423 --> 00:58:49,157
And that's usually worth filling if the object is gonna
而这通常是值得如果对象是要填充

1308
00:58:49,225 --> 00:58:50,992
be fairly large,
是相当大的,

1309
00:58:51,061 --> 00:58:54,929
The API to use in SQLite directly looks like c,
API直接使用SQLite看起来像c,

1310
00:58:54,998 --> 00:58:58,834
Not surprisingly it's not object oriented in any way
毫不奇怪它不是面向对象的

1311
00:58:58,902 --> 00:59:03,338
it's just classic single SQL call there's functions that
只是典型的单一SQL调用的函数

1312
00:59:03,407 --> 00:59:06,041
you pass SQL language to basically,
你基本上通过SQL语言,

1313
00:59:06,109 --> 00:59:10,178
And it executes it and even though core data uses it you
它执行,即使核心数据使用它

1314
00:59:10,247 --> 00:59:14,216
don't see it from core data directly,
不要直接看到它从核心数据,

1315
00:59:14,284 --> 00:59:16,985
You know, there's a new probably use SQL is
你知道,有一个新的可能使用SQL

1316
00:59:17,054 --> 00:59:20,222
if you had some existing database or something,
如果你有一些现有的数据库,

1317
00:59:20,290 --> 00:59:21,256
The file system,
文件系统,

1318
00:59:21,325 --> 00:59:24,292
now the file system is something that I would imagine
现在是我想象的文件系统上

1319
00:59:24,361 --> 00:59:27,228
some of you might want to use in your final project,
你们中的一些人可能想要使用在你最后的项目中,

1320
00:59:27,297 --> 00:59:32,233
And your access to the Unix filesystem that underlies
和你的Unix文件系统的访问

1321
00:59:32,302 --> 00:59:37,238
your application is a little bit limited,
您的应用程序是有限的一点,

1322
00:59:37,307 --> 00:59:41,409
And so the way that you access it is generally be used four
所以,你通常使用四个访问它

1323
00:59:41,478 --> 00:59:42,377
steps,
步骤,

1324
00:59:42,445 --> 00:59:47,582
First you're gonna get a URL into the Unix filesystem and
首先你会得到一个URL到Unix文件系统

1325
00:59:47,651 --> 00:59:50,585
there are about 20 preset points
大约有20个预置点

1326
00:59:50,654 --> 00:59:53,288
in the Unix filesystem that you can get a URL to,
你可以得到一个URL的Unix文件系统,

1327
00:59:54,391 --> 00:59:56,257
And once you've got that URL,
一旦你理解了这个网址,

1328
00:59:56,326 --> 00:59:58,593
then you can create directories there,
然后您可以创建目录,

1329
00:59:58,662 --> 01:00:02,464
Create files there by taking your URL and adding path
创建文件的URL和添加路径

1330
01:00:02,532 --> 01:00:06,134
components to it to describe directories and files,
组件描述目录和文件,

1331
01:00:06,203 --> 01:00:08,102
Then you write to the files,
然后你写文件,

1332
01:00:08,171 --> 01:00:11,573
you're usually doing this with the data object,
你通常做这个数据对象,

1333
01:00:11,641 --> 01:00:14,843
Or there's some property lists methods that can write out
或者有一些属性列表的方法,可以写出来

1334
01:00:14,911 --> 01:00:16,778
to a file,
到一个文件中,

1335
01:00:16,847 --> 01:00:19,914
And then finally you're gonna manage all those files with
最后你要管理所有这些文件

1336
01:00:19,983 --> 01:00:21,617
a class called a file manager,
一个类称为一个文件管理器,

1337
01:00:21,685 --> 01:00:23,585
So the file manager lets you copy files and
文件管理器允许你复制文件和

1338
01:00:23,653 --> 01:00:25,820
remove files and list files and directories,
删除文件和文件和目录列表,

1339
01:00:25,889 --> 01:00:28,023
And all the things you can do with a file system,
和所有的事情你可以做一个文件系统,

1340
01:00:28,092 --> 01:00:29,323
you do with a file manager,
你做一个文件管理器,

1341
01:00:29,392 --> 01:00:32,527
So these are the main aspects of accessing the file system,
这是访问文件系统的主要方面,

1342
01:00:32,596 --> 01:00:34,096
So let's look at each of these things,
让我们看看这些东西,

1343
01:00:35,698 --> 01:00:38,967
It's a Unix filesystem it starts at root of course it's
这是一个Unix文件系统从根开始当然是

1344
01:00:39,036 --> 01:00:40,402
protected, there's permissions,
保护,有权限,

1345
01:00:40,470 --> 01:00:43,638
So you can't go writing files into system directories or
所以你不能写文件到系统目录或去

1346
01:00:43,707 --> 01:00:45,206
even reading a lot of the system directories,
即使阅读很多系统的目录,

1347
01:00:45,275 --> 01:00:47,608
And you certainly can't see other apps
你当然不能看到其他应用程序

1348
01:00:47,677 --> 01:00:48,476
what they're doing over there,
他们在做什么,

1349
01:00:48,545 --> 01:00:51,646
That's completely off limits there,
完全禁止的,

1350
01:00:51,715 --> 01:00:54,615
In fact, you can only write and
事实上,你只能写信

1351
01:00:54,684 --> 01:00:58,019
read inside what's called your application's sandbox,
读所谓的内部应用程序的沙盒,

1352
01:00:58,088 --> 01:01:02,223
So sandbox is this totally segregated part of the file
这是沙盒完全隔离的文件的一部分

1353
01:01:02,292 --> 01:01:05,227
system,
系统,

1354
01:01:05,295 --> 01:01:05,760
do things,
做事情,

1355
01:01:05,828 --> 01:01:07,996
And now why do we have a sandbox?
现在为什么我们有一个沙盒?

1356
01:01:08,065 --> 01:01:10,365
It might seem obvious to you for some things,
有些东西,似乎明显的你了

1357
01:01:10,433 --> 01:01:13,334
For example security is a big one,
例如安全是一个大的,

1358
01:01:13,403 --> 01:01:16,338
We don't want other apps to be able to reach into your app
我们不想让其他应用程序可以进入你的应用

1359
01:01:16,406 --> 01:01:17,538
and damage you,
和伤害你,

1360
01:01:17,607 --> 01:01:18,973
That would be really bad,
这将是非常糟糕的,

1361
01:01:19,042 --> 01:01:20,775
So we gotta have security for that,
所以我们要有安全,

1362
01:01:20,844 --> 01:01:22,610
There's privacy, we wouldn't want those other apps to
有隐私,我们不想让其他应用程序

1363
01:01:22,679 --> 01:01:26,447
be able to look inside you and see your private data either,
能看在你和看到你的私人数据,

1364
01:01:26,516 --> 01:01:29,818
But another interesting reason that you wouldn't maybe
但也许你不会另一个有趣的原因

1365
01:01:29,886 --> 01:01:31,052
think of is clean up,
认为的清理,

1366
01:01:31,121 --> 01:01:35,623
If someone deletes your app from their phone entirely they
如果有人从他们的手机完全删除应用程序

1367
01:01:35,692 --> 01:01:40,361
want everything this app has ever created to be gone,
想要一切这个程序所创建的走了,

1368
01:01:40,430 --> 01:01:43,164
And by having the sandbox, and that's the only place you can
通过沙盒,这是唯一的地方

1369
01:01:43,233 --> 01:01:45,934
write, when you delete, it deletes your entire sandbox,
写,当你删除,删除整个沙盒,

1370
01:01:46,003 --> 01:01:48,503
So anything you've ever created is gone,
所以任何你曾经创建了,

1371
01:01:48,572 --> 01:01:50,405
So you don't have to worry about people writing
所以你不必担心人们写作

1372
01:01:50,474 --> 01:01:52,373
things into system directories and all of that,
到系统目录和所有的东西,

1373
01:01:52,442 --> 01:01:54,509
Which happens all over the place on the Mac for
这到处都发生在Mac上

1374
01:01:54,578 --> 01:01:57,112
example, you're home directory slash library has got
例子,你主目录削减图书馆了

1375
01:01:57,181 --> 01:01:58,413
all kinds of junk in there,
各种各样的垃圾,

1376
01:01:58,482 --> 01:02:01,215
They don't have the same concept there of everything
他们没有相同的概念的一切

1377
01:02:01,284 --> 01:02:03,185
being isolated like you have in iOS,
在iOS孤立的喜欢你,

1378
01:02:03,253 --> 01:02:05,187
So it's actually a cool feature have the sandbox,
这实际上是一个很酷的功能有沙箱,

1379
01:02:06,622 --> 01:02:10,024
Now inside the sandbox there are certain directories that
现在在沙箱有特定的目录

1380
01:02:10,093 --> 01:02:12,828
you can get URL too, I can says about 20 of them,
你可以得到URL,我能说大约20人,

1381
01:02:12,896 --> 01:02:14,829
So for example, there's the application directory
例如,应用程序目录

1382
01:02:14,898 --> 01:02:17,632
that's where your applications binary is,
这就是应用程序二进制文件,

1383
01:02:17,701 --> 01:02:21,168
You can only read and In there read only, you cannot write
你只能读和只读,你不能写

1384
01:02:21,237 --> 01:02:23,838
to your own application no self modifying code allowed,
到您自己的应用程序不允许自修改代码,

1385
01:02:23,907 --> 01:02:25,974
in IOS,
在IOS,

1386
01:02:26,042 --> 01:02:28,376
This is also where you might have things JPEG's or
这也是在JPEG或你可能有事情

1387
01:02:28,445 --> 01:02:31,079
other things if you don't use the image assets things,
其他东西如果你不使用资产的东西的图片,

1388
01:02:31,148 --> 01:02:33,081
You can actually just drag JPEG's or
你可以直接将JPEG或

1389
01:02:33,150 --> 01:02:35,316
whatever directory into your project,
任何目录到您的项目,

1390
01:02:35,385 --> 01:02:38,619
And they'll appear in you application bundle you
他们会出现在你的应用程序包

1391
01:02:38,688 --> 01:02:40,522
can look at the directly,
可以直接看,

1392
01:02:41,725 --> 01:02:43,892
We rarely do that, by the way,
我们很少做,顺便说一下,

1393
01:02:43,961 --> 01:02:46,228
But other URL's that you can look in there that
但是其他的网址,你可以看看

1394
01:02:46,296 --> 01:02:47,095
are kinda cool,
是有点酷,

1395
01:02:47,163 --> 01:02:49,530
There's the documents directory, that's a big one,
文件目录,这是一个大的,

1396
01:02:49,599 --> 01:02:52,299
That's where you're gonna put user created data
这就是你要把用户创建的数据

1397
01:02:52,368 --> 01:02:53,535
that the user cares about,
用户关心的,

1398
01:02:54,971 --> 01:02:56,804
What the user perceives as their documents,
用户感知的文档,

1399
01:02:56,873 --> 01:02:59,674
Even if you don't have a document oriented application
即使你没有一个面向文档的应用程序

1400
01:02:59,742 --> 01:03:01,742
the user considers that as like that's their data,
用户认为,这样的数据,

1401
01:03:01,811 --> 01:03:03,244
That's what they entered,
这是他们进入,

1402
01:03:03,313 --> 01:03:05,379
Now you're app might store that on the network,
现在你的应用程序可能会存储在网络上,

1403
01:03:05,448 --> 01:03:08,516
So maybe
所以也许

1404
01:03:08,585 --> 01:03:11,553
Or your app is just not the kind of app that has data like
或应用程序不是这样的应用程序数据

1405
01:03:11,622 --> 01:03:12,387
that, fine,
,很好,

1406
01:03:12,456 --> 01:03:14,422
But if it does the documents directory is
但如果它的文件目录

1407
01:03:14,490 --> 01:03:16,591
your primary place you're gonna store stuff,
你要存储的东西,你的主要地方

1408
01:03:16,660 --> 01:03:18,693
But sometimes the user creates things and
但有时用户创建的东西,

1409
01:03:18,762 --> 01:03:20,428
you're really just cashing it,
你真的只是兑现,

1410
01:03:20,496 --> 01:03:21,162
So for example,
举个例子,

1411
01:03:21,231 --> 01:03:24,666
let's go back to our Twitter client, Smashtag,
让我们回到我们的Twitter客户端,Smashtag,

1412
01:03:24,735 --> 01:03:27,735
In Smashtag we downloaded images and
在Smashtag我们图片和下载

1413
01:03:27,804 --> 01:03:30,939
maybe we wanted to keep the images that
也许我们想要的图像

1414
01:03:31,008 --> 01:03:34,809
were associated with the image tab local,
当地与图像相关的标签,

1415
01:03:34,878 --> 01:03:36,010
That way I'm local even
我甚至当地

1416
01:03:36,079 --> 01:03:38,113
though I'm not connected to the network,
虽然我没有连接到网络,

1417
01:03:38,181 --> 01:03:41,115
But those aren't really user data their just something I
但这些并不是真的只是我用户数据

1418
01:03:41,184 --> 01:03:42,217
wanna cache,
想要缓存,

1419
01:03:42,285 --> 01:03:45,687
I just want to keep them local so for ease of use,
我只是想让他们当地的易用性,

1420
01:03:45,756 --> 01:03:47,589
But as things go out of recent,
但作为最近的事情出去,

1421
01:03:47,658 --> 01:03:49,524
I'd probably clear them out,
我可能清晰,

1422
01:03:49,593 --> 01:03:52,694
And if that cache directory got completely cleared out it
如果缓存目录完全清除它

1423
01:03:52,762 --> 01:03:55,497
would be fine I'd just reload them all again,
会好我再重新加载它们,

1424
01:03:55,565 --> 01:03:57,065
So the caches directory is a place
因此,缓存目录是一个地方

1425
01:03:57,133 --> 01:03:58,967
to put stuff that you can easily get again,
再把东西可以很容易地得到,

1426
01:04:00,537 --> 01:04:02,904
Images and stuff that you're caching,
图片和东西你缓存,

1427
01:04:02,973 --> 01:04:05,373
And there's a bunch of other directories,
还有很多其他目录,

1428
01:04:05,441 --> 01:04:07,141
I don't have time to talk about all of them,
我没有时间谈论他们所有人,

1429
01:04:07,210 --> 01:04:08,809
unfortunately,
不幸的是,

1430
01:04:08,878 --> 01:04:11,045
So how do we get our URL to one of these special
那么,我们如何让我们的这些特殊的URL

1431
01:04:11,114 --> 01:04:13,181
directories like the document structure or
目录的文档结构

1432
01:04:13,250 --> 01:04:15,516
the caches directory, things like that?
缓存目录,类似这样的事情吗?

1433
01:04:15,585 --> 01:04:18,086
We're gonna use this another default,
我们将使用这个另一个默认的,

1434
01:04:18,154 --> 01:04:21,355
just like we had in in this notification center,default,
就像我们在通知中心,默认情况下,

1435
01:04:21,424 --> 01:04:23,625
Now we have FileManager,default,
现在我们有文件管理,默认情况下,

1436
01:04:23,694 --> 01:04:26,261
So the FileManager is the thing that lets you
文件管理是让你的东西

1437
01:04:26,329 --> 01:04:27,595
manage the entire file system, and
管理整个文件系统,

1438
01:04:27,664 --> 01:04:30,398
it has a default one that you can use,
它有一个默认的一个,您可以使用,

1439
01:04:30,467 --> 01:04:33,668
And it has a method called URLs for
它有一个名为url的方法

1440
01:04:33,737 --> 01:04:36,637
directory in domainMask, okay,
目录domainMask,好吧,

1441
01:04:36,706 --> 01:04:38,540
That's this method you see right here,
这个方法你看到这里,

1442
01:04:38,608 --> 01:04:41,275
And it gives you an array of URLs,
它给你一个url数组,

1443
01:04:41,344 --> 01:04:45,146
In iOS, there's only ever one URL in there,
在iOS,只能有一个URL,

1444
01:04:45,215 --> 01:04:48,816
The reason this is an array on desktop machines like the Mac,
之所以这是一个数组像Mac台式机,

1445
01:04:48,885 --> 01:04:52,854
sometimes you'll have like a library directory that has
有时,你会像一个图书馆目录

1446
01:04:52,923 --> 01:04:55,155
one for the user, one on the network so
一个用于用户,另一个在网络上

1447
01:04:55,224 --> 01:04:56,157
there's multiple of them,
有多种,

1448
01:04:56,226 --> 01:04:59,760
But in iOS all things are inside the sandbox so
但在iOS沙箱内都是如此

1449
01:04:59,829 --> 01:05:03,765
the only domain, that's why the user domain mask there is
唯一的领域,这就是为什么用户域的面具

1450
01:05:03,834 --> 01:05:05,866
user domain mask,
用户域的面具,

1451
01:05:05,935 --> 01:05:07,701
So there's only ever one URL,
所以只有一个URL,

1452
01:05:07,770 --> 01:05:09,804
So there's only one URL for your documents directory,
所以只有一个URL文档目录,

1453
01:05:09,872 --> 01:05:11,405
One URL for your caches directory,
一个URL缓存目录,

1454
01:05:11,474 --> 01:05:13,841
One URL for your documentation directory,
一个URL为你的文档目录,

1455
01:05:13,910 --> 01:05:15,977
One URL for your application, okay, just one,
一个URL为您的应用程序,只有一个,

1456
01:05:16,046 --> 01:05:18,546
Just the one in the sandbox,
只是一个沙箱中

1457
01:05:18,615 --> 01:05:21,882
So you specify which directory you want with that
所以你指定目录

1458
01:05:21,951 --> 01:05:24,051
argument therefore directory,
因此参数目录,

1459
01:05:24,120 --> 01:05:25,386
And that has to be a type
这是一个类型

1460
01:05:25,454 --> 01:05:27,622
FileManager,SearchPathDirect- ory,
SearchPathDirect文件管理——理论、

1461
01:05:27,691 --> 01:05:29,691
So again, look that up in the documentation and
所以,看在文档和

1462
01:05:29,759 --> 01:05:32,694
you'll see the various directories in your sandbox
你会看到各种目录沙箱中

1463
01:05:32,762 --> 01:05:33,394
that you can look at,
你可以看看,

1464
01:05:33,463 --> 01:05:35,130
There's about 20 of them,
大约有20人,

1465
01:05:35,198 --> 01:05:37,031
And if you are the document director for example,
如果你是文档总监为例,

1466
01:05:37,100 --> 01:05:39,700
you say ,documentDirectory right there,
你说,documentDirectory,

1467
01:05:39,769 --> 01:05:42,203
And it will give you back an array where there is only one
,它会给你一个数组只有一个

1468
01:05:42,271 --> 01:05:47,008
thing in there,
在那里,

1469
01:05:47,076 --> 01:05:49,777
document directory in your sandbox,
在你的沙箱文档目录,

1470
01:05:49,846 --> 01:05:50,445
Make sense?
有意义吗?

1471
01:05:51,748 --> 01:05:53,647
So that's how we get in,
这就是我们,

1472
01:05:53,716 --> 01:05:57,585
Once we get in, we want to create directories in there,
一旦我们得到,我们要创建目录,

1473
01:05:57,654 --> 01:05:59,386
create files, whatever,
创建文件,无论如何,

1474
01:05:59,455 --> 01:06:01,122
We, or access files,
我们,或访问文件,

1475
01:06:01,191 --> 01:06:05,292
We do those by using these appending methods in URL,
我们做这些URL,通过使用这些附加方法

1476
01:06:05,361 --> 01:06:07,929
So we have that URL and we send a message to the URL,
所以我们有URL发送消息到一个网址,

1477
01:06:07,998 --> 01:06:12,233
Like give me a new URL by URL appendingPathComponent
像给我一个新的URL appendingPathComponent通过URL

1478
01:06:12,302 --> 01:06:14,869
whatever the name of my directory or the name of
无论我目录的名字或名称

1479
01:06:14,938 --> 01:06:18,006
the file that I want or by appending path extension, so
我想要的文件,或通过添加路径扩展,所以

1480
01:06:18,074 --> 01:06:21,743
,jpeg, or something like that, so I can get my jpeg file,
、jpeg或类似的东西,所以我可以得到我的jpeg文件,

1481
01:06:21,812 --> 01:06:24,645
So by doing that I build a path, the URL,
我建立一个路径,通过URL,

1482
01:06:24,714 --> 01:06:25,647
to the file I want,
我想要到文件,

1483
01:06:27,250 --> 01:06:29,917
So that's how I navigate around in my sand box,
这就是我在砂箱,浏览

1484
01:06:29,986 --> 01:06:31,920
So now I have the URL and
所以现在我有URL和

1485
01:06:31,989 --> 01:06:35,156
I can do a lot of things with that URL,
我可以做很多事情,网址,

1486
01:06:35,225 --> 01:06:37,992
I'll show you in a moment how you can write files out and
我将向您展示如何编写文件,

1487
01:06:38,061 --> 01:06:40,928
things like that but you can also find out about things URL
之类的东西,但你也可以了解事情的URL

1488
01:06:40,997 --> 01:06:42,664
like is this a file?
像这一个文件吗?

1489
01:06:42,732 --> 01:06:44,565
Or is it a directory?
还是一个目录?

1490
01:06:44,634 --> 01:06:46,133
Or is it on the network for example?
比如还是网络上的吗?

1491
01:06:46,202 --> 01:06:48,102
Cuz you have a URL that someone gives you,
因为你有一个URL,有人给你,

1492
01:06:48,171 --> 01:06:49,203
maybe it's a network URL,
也许这是一个网络网址,

1493
01:06:49,272 --> 01:06:51,472
Http, colon, slash, slash, something,
Http、结肠削减,削减,东西,

1494
01:06:51,541 --> 01:06:55,109
Well that's not a file URL so is file, file URL right there,
这不是一个文件URL所以文件,文件的URL,

1495
01:06:55,178 --> 01:06:57,778
we tell you that it's in the file system,
我们告诉你,这是在文件系统中,

1496
01:06:57,847 --> 01:07:01,983
A really powerful method in URL is resourceValues for
一个真正强大的方法在URL是resourceValues

1497
01:07:02,052 --> 01:07:03,017
keys,
键,

1498
01:07:03,085 --> 01:07:06,287
So resource values for keys you give it an array of keys
所以资源值键你给它一个数组的键

1499
01:07:06,356 --> 01:07:08,422
that are attributes of files,
文件的属性,

1500
01:07:08,491 --> 01:07:11,392
these keys are attributes of files, like the files size, or
这些键的属性文件,文件大小,或

1501
01:07:11,461 --> 01:07:13,794
the files creation date, or whatever,
文件创建日期,等等,

1502
01:07:13,863 --> 01:07:17,331
And it will return you a dictionary with those keys and
它会返回你与钥匙和一本字典

1503
01:07:17,400 --> 01:07:19,200
the values for the file, for
文件,的值

1504
01:07:19,269 --> 01:07:20,801
the URL that you're pointing to,
你指向的URL,

1505
01:07:20,870 --> 01:07:22,503
So that's how you can find out the size of the file,
这就是你可以找到的文件的大小,

1506
01:07:22,572 --> 01:07:25,406
where the creationDate or whether isDirectory,
创建日期或者是否isDirectory,

1507
01:07:25,475 --> 01:07:26,441
Things like that,
类似这样的事情,

1508
01:07:26,509 --> 01:07:29,343
Notice the listing throws so be careful here,
注意这里的清单把所以要小心,

1509
01:07:29,412 --> 01:07:30,712
You have to do this in a try,
你要做这个尝试,

1510
01:07:34,851 --> 01:07:36,617
How about writing files out to the file system,
如何写文件到文件系统,

1511
01:07:36,686 --> 01:07:39,586
Well mostly we do this with a data,
我们主要做这个数据,

1512
01:07:39,655 --> 01:07:42,724
If you have for example a UI image and
如果你有例如UI和形象

1513
01:07:42,792 --> 01:07:44,492
you wanna store on your screen, or
你想要存储在你的屏幕上,或

1514
01:07:44,560 --> 01:07:46,293
whatever that you downloaded from the internet, and
无论你从互联网上下载

1515
01:07:46,362 --> 01:07:48,963
you wanna store that into the file system,
你想要存储到文件系统中,

1516
01:07:49,031 --> 01:07:51,766
there's actually a cool function called, I think,
有一个很酷的功能,我认为,

1517
01:07:51,835 --> 01:07:55,502
UI image jpeg representation or something like that,
UI图像jpeg代表之类的,

1518
01:07:55,571 --> 01:07:59,006
And you give it a UI image, and it will return a data,
你给它一个UI的形象,它将返回一个数据,

1519
01:07:59,075 --> 01:08:02,443
And a data will have the data of the jpeg image,
和数据将jpeg图像的数据,

1520
01:08:02,512 --> 01:08:03,244
That you can store,
你可以存储,

1521
01:08:03,312 --> 01:08:05,913
And then you can say write to url,
然后你可以说写网址,

1522
01:08:05,982 --> 01:08:09,584
So this is a data method here write to URL atomically,
这是一个URL自动数据方法编写,

1523
01:08:09,653 --> 01:08:11,519
And then we'll write it out to that URL,
然后我们会把它写出来,网址,

1524
01:08:11,588 --> 01:08:13,954
So you have to build yourself URL like get in the sandbox
所以你必须建立自己的URL像沙箱

1525
01:08:14,023 --> 01:08:16,657
directory, and then depending whatever name you want to it,
目录,然后根据任何你想要的名字,

1526
01:08:16,726 --> 01:08:19,227
Then you say write to URL, atomically just means it'll
然后你说写网址,自动就意味着它会

1527
01:08:19,296 --> 01:08:21,362
safely, it'll write it to a temp file first and
安全,它会先到一个临时文件,写下来

1528
01:08:21,431 --> 01:08:24,031
then swap it in so if you ran out of disk space
然后交换在如果你耗尽磁盘空间

1529
01:08:24,100 --> 01:08:26,734
while writing it or something it wouldn't corrupt if a file
在写什么的不会腐败的如果一个文件

1530
01:08:26,802 --> 01:08:29,403
that was already there for example,
这已经为例,

1531
01:08:29,472 --> 01:08:33,541
Now, to get the data object back you just use the same
现在,你只是使用相同的数据对象

1532
01:08:33,610 --> 01:08:38,345
initializer you used when we did some hashtag or
初始化你当我们做了一些标签或使用

1533
01:08:38,414 --> 01:08:40,648
the lecture before that,
演讲之前,

1534
01:08:40,717 --> 01:08:43,551
what we said data init, contents of URL,
我们说,数据初始化,URL的内容,

1535
01:08:43,620 --> 01:08:44,352
Now in that case,
现在在这种情况下,

1536
01:08:44,421 --> 01:08:47,421
if the URL was a network URL and it blocked the main queue,
如果URL是一个URL和网络封锁了主要队列,

1537
01:08:47,490 --> 01:08:50,758
here that URL could be a file system URL,
URL可以是一个文件系统URL,

1538
01:08:50,827 --> 01:08:52,960
And it wouldn't block the main queue,
它不会阻止主队列,

1539
01:08:53,029 --> 01:08:55,262
Loading files up super fast,
加载文件非常快,

1540
01:08:55,331 --> 01:08:57,866
So you don't really need to do that in a separate
你真的不需要这样做在一个单独的

1541
01:08:59,202 --> 01:09:01,101
thread unless maybe it was a gigantic file,
线程,除非可能是一个巨大的文件,

1542
01:09:01,170 --> 01:09:03,304
But even then, maybe you could do that, yeah question,
但即使这样,也许你可以这样做,是的问题,

1543
01:09:03,372 --> 01:09:07,041
When would you not wanna do atomically right here?
当你不会想做自动呢?

1544
01:09:07,110 --> 01:09:08,876
It's hard for me to even think of an example with that,
甚至对我来说很难想到的一个例子,

1545
01:09:08,944 --> 01:09:11,579
Maybe it's a really huge file and
也许这是一个非常巨大的文件

1546
01:09:11,648 --> 01:09:13,381
you don't wanna create two copies of it,
你不想创建两个副本,

1547
01:09:13,450 --> 01:09:15,516
The safe copy and then over, and so
安全的副本,然后结束,所以

1548
01:09:15,585 --> 01:09:18,686
you've got an existing copy of a huge file, let's say,
你有现有的复制一个巨大的文件,比方说,

1549
01:09:18,755 --> 01:09:21,655
And you don't wanna create another copy of it
你不想创建另一个副本

1550
01:09:21,724 --> 01:09:23,758
as a safe copy before you move it in, so,
作为安全复制在你移动,所以,

1551
01:09:23,827 --> 01:09:25,293
that you might say atomically no so,
你可能说自动不如此,

1552
01:09:25,361 --> 01:09:28,863
it just destroys your old one right off of that, I mean,
它只是破坏你的旧的,我的意思是,

1553
01:09:28,932 --> 01:09:30,597
I'm really stretching to think of good example,
我真的拉伸的很好的例子,

1554
01:09:30,666 --> 01:09:33,768
you almost always want true to there,
你总是想要真实,

1555
01:09:33,836 --> 01:09:36,904
So, that's how you read and write files with data,
这就是你如何读取和写入文件的数据,

1556
01:09:36,973 --> 01:09:38,539
very common way to do that,
很常见的方法,

1557
01:09:38,607 --> 01:09:41,709
Once you've written out files, you want to be able to go
一旦写入文件,你希望能够去

1558
01:09:41,778 --> 01:09:44,946
through your file system and like look at what files are in
通过你的文件系统,并像看看文件

1559
01:09:45,015 --> 01:09:47,381
certain directories or things like that,
某些目录或类似的东西,

1560
01:09:47,450 --> 01:09:49,484
Maybe you've got caches out there and
也许你已经有了和缓存

1561
01:09:49,552 --> 01:09:51,953
you want to see what's in your cache or whatever,
你想看看你的缓存之类的,

1562
01:09:52,021 --> 01:09:53,488
And that's what FileManager's for,
这就是文件管理的,

1563
01:09:53,556 --> 01:09:56,590
It has dozens of methods for doing that like,
这有许多方法来做,

1564
01:09:56,659 --> 01:09:59,994
createDirectory( at url, which will create a directory for
createDirectory(url,这将创建一个目录

1565
01:10:00,062 --> 01:10:02,396
you so you can put files in there,
你在那里,你可以把文件

1566
01:10:02,465 --> 01:10:06,433
And it also has a bunch, it has a delegate,
它也有很多,它有一个委托,

1567
01:10:06,502 --> 01:10:08,403
And a bunch of shoulds,
和一群应该,

1568
01:10:08,471 --> 01:10:11,372
Should I allow creating this file?
我应该允许创建这个文件吗?

1569
01:10:11,441 --> 01:10:14,341
Things like that,
类似这样的事情,

1570
01:10:14,410 --> 01:10:18,813
The FileManager by the way is thread safe in the same way
文件管理的方法是线程安全的方式都是一样的

1571
01:10:18,882 --> 01:10:21,916
that an NSManagedObjectContext is thread safe,
一个NSManagedObjectContext是线程安全的,

1572
01:10:21,985 --> 01:10:25,552
In other words, if you create the FileManager on a certain
换句话说,如果您创建特定的文件管理

1573
01:10:25,621 --> 01:10:29,389
thread then it's always thread safe to use it in that thread,
线程就总是在线程,线程安全的使用它

1574
01:10:29,458 --> 01:10:31,959
in that same queue,
在同一队列,

1575
01:10:32,028 --> 01:10:34,661
If you create a FileManager on a different one,
如果您创建了一个在另一个文件管理,

1576
01:10:34,730 --> 01:10:37,231
that one's safe to use in its queue and
一个队列和安全使用

1577
01:10:37,300 --> 01:10:39,901
they will work together as well,
他们将在一起工作,

1578
01:10:39,969 --> 01:10:43,004
Just don't try to use a FileManager created in one
只是不要尝试使用在一个创建的文件管理

1579
01:10:43,072 --> 01:10:44,638
thread over on a different thread,
线程在一个不同的线程,

1580
01:10:44,707 --> 01:10:45,974
That is not thread safe,
这不是线程安全的,

1581
01:10:47,209 --> 01:10:51,712
It's just like how NSManagedObjectContext is
就像NSManagedObjectContext

1582
01:10:51,781 --> 01:10:53,581
thread safe,
线程安全的,

1583
01:10:53,650 --> 01:10:56,951
That is it for this lecture so the coming up we have
这是这节课我们的到来

1584
01:10:57,019 --> 01:11:00,387
is accessibility is our next lecture on Monday and
可访问性是星期一,我们下一节课吗

1585
01:11:00,456 --> 01:11:04,491
also your slides are due for the alternate final there,
还你的幻灯片将替代最后那里,

1586
01:11:04,560 --> 01:11:05,193
Do not forget that,
不要忘记,

1587
01:11:05,261 --> 01:11:06,027
I put it in red,
我把它放在红色,

1588
01:11:07,429 --> 01:11:10,698
How many people,
有多少人,

1589
01:11:12,201 --> 01:11:14,902
A few of you, so make sure you get your slides in,
的你,所以确保你得到你的幻灯片,

1590
01:11:14,971 --> 01:11:17,671
Wednesday will be the alternate final itself,
周三将会替代最终本身,

1591
01:11:17,740 --> 01:11:20,674
Your final project is due the Sunday after that,
最终项目定于周日之后,

1592
01:11:20,743 --> 01:11:23,645
the Sunday the 19th of March, at midnight,
在午夜,周日3月19

1593
01:11:25,448 --> 01:11:26,613
That is it,
这是它,

1594
01:11:26,682 --> 01:11:29,517
I will see you all on Monday,
周一我将看到你所有,

1595
01:11:29,586 --> 01:11:40,194
>> For more please visit us at www,stanford,edu
> >更多信息请访问我们在www,斯坦福大学,埃杜