StorageFiles.md

title	author	description	keywords	dev_langs
StorageFileHelper	nmetulev	The StorageFileHelper is a static utility class that provides functions to help with reading and writing of text and bytes to the disk. These functions are all wrapped into Async tasks.	windows 10, uwp, windows community toolkit, uwp community toolkit, uwp toolkit, StorageFileHelper	csharp vb

StorageFileHelper

The StorageFileHelper is a static utility class that provides functions to help with reading and writing of text and bytes to the disk. These functions are all wrapped into Async tasks.

Syntax

// NOTE This must be used from an async function
string myText = "Great information that the users wants to keep";
StorageFolder localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;

// Save some text to a file named appFilename.txt (in the local cache folder)
var storageFile = await StorageFileHelper.WriteTextToLocalCacheFileAsync(myText, "appFilename.txt");

// Load some text from a file named appFilename.txt in the local cache folder 
string loadedText = await StorageFileHelper.ReadTextFromLocalCacheFileAsync("appFilename.txt");

// Save some text to a file named appFilename.txt (in the local folder)
storageFile = await StorageFileHelper.WriteTextToLocalFileAsync(myText, "appFilename.txt");

// Load some text from a file named appFilename.txt in the local folder 
loadedText = await StorageFileHelper.ReadTextFromLocalFileAsync("appFilename.txt");

// Check if a file exists in a specific folder
bool exists = await localFolder.FileExistsAsync("appFilename.txt");

// Check if a file exists in a specific folder or in one of its subfolders
bool exists = await localFolder.FileExistsAsync("appFilename.txt", true);

// Check if a file name is valid or not
bool isFileNameValid = StorageFileHelper.IsFileNameValid("appFilename.txt");

// Check if a file path is valid or not
bool isFilePathValid = StorageFileHelper.IsFilePathValid("folder/appFilename.txt");

' NOTE This must be used from an async function
Dim myText As String = "Great information that the users wants to keep"
Dim localFolder As StorageFolder = Windows.Storage.ApplicationData.Current.LocalFolder

' Save some text to a file named appFilename.txt (in the local cache folder)
Dim storageFile = Await StorageFileHelper.WriteTextToLocalCacheFileAsync(myText, "appFilename.txt")

' Load some text from a file named appFilename.txt in the local cache folder 
Dim loadedText As String = Await StorageFileHelper.ReadTextFromLocalCacheFileAsync("appFilename.txt")

' Save some text to a file named appFilename.txt (in the local folder)
storageFile = Await StorageFileHelper.WriteTextToLocalFileAsync(myText, "appFilename.txt")

' Load some text from a file named appFilename.txt in the local folder 
loadedText = Await StorageFileHelper.ReadTextFromLocalFileAsync("appFilename.txt")

' Check if a file exists in a specific folder
Dim exists As Boolean = Await localFolder.FileExistsAsync("appFilename.txt")

' Check if a file exists in a specific folder or in one of its subfolders
Dim exists As Boolean = Await localFolder.FileExistsAsync("appFilename.txt", True)

' Check if a file name is valid or not
Dim isFileNameValid As Boolean = StorageFileHelper.IsFileNameValid("appFilename.txt")

' Check if a file path is valid or not
Dim isFilePathValid As Boolean = StorageFileHelper.IsFilePathValid("folder/appFilename.txt")

Methods

Methods	Return Type	Description
FileExistsAsync(StorageFolder, String, Boolean)	Task<bool>	Gets a value indicating whether a file exists in the current folder
IsFileNameValid(String)	bool	Gets a value indicating whether a filename is correct or not using the Storage feature
IsFilePathValid(String)	bool	Gets a value indicating whether a file path is correct or not using the Storage feature
ReadBytesAsync(StorageFile)	Task<byte[]>	Gets an array of bytes from a StorageFile
ReadBytesFromFileAsync(StorageFolder, String)	Task<byte[]>	Gets an array of bytes from a StorageFile located in the given StorageFolder
ReadBytesFromKnownFoldersFileAsync(KnownFolderId, String)	Task<byte[]>	Gets an array of bytes from a StorageFile located in a well known folder
ReadBytesFromLocalCacheFileAsync(String)	Task<byte[]>	Gets an array of bytes from a StorageFile located in the application local cache folder
ReadBytesFromLocalFileAsync(String)	Task<byte[]>	Gets an array of bytes from a StorageFile located in the application local folder
ReadBytesFromPackagedFileAsync(String)	Task<byte[]>	Gets an array of bytes from a StorageFile located in the application installation folder
ReadTextFromFileAsync(StorageFolder, String)	Task<string>	Gets a string value from a StorageFile located in the given StorageFolder
ReadTextFromKnownFoldersFileAsync(KnownFolderId, String)	Task<string>	Gets a string value from a StorageFile located in a well known folder
ReadTextFromLocalCacheFileAsync(String)	Task<string>	Gets a string value from a StorageFile located in the application local cache folder
ReadTextFromLocalFileAsync(String)	Task<string>	Gets a string value from a StorageFile located in the application local folder
ReadTextFromPackagedFileAsync(String)	Task<string>	Gets a string value from a StorageFile located in the application installation folder
WriteBytesToFileAsync(StorageFolder, Byte[], String, CreationCollisionOption)	Task<StorageFile>	Saves an array of bytes to a StorageFile in the given StorageFolder
WriteBytesToKnownFolderFileAsync(KnownFolderId, Byte[], String, CreationCollisionOption)	Task<StorageFile>	Saves an array of bytes to a StorageFile to well known folder
WriteBytesToLocalCacheFileAsync(Byte[], String, CreationCollisionOption)	Task<StorageFile>	Saves an array of bytes to a StorageFile to application local cache folder
WriteBytesToLocalFileAsync(Byte[], String, CreationCollisionOption)	Task<StorageFile>	Saves an array of bytes to a StorageFile to application local folder
WriteTextToFileAsync(StorageFolder, String, String, CreationCollisionOption)	Task<StorageFile>	Saves a string value to a StorageFile in the given StorageFolder
WriteTextToKnownFolderFileAsync(KnownFolderId, String, String, CreationCollisionOption)	Task<StorageFile>	Saves a string value to a Windows.Storage.StorageFile in well known folder
WriteTextToLocalCacheFileAsync(String, String, CreationCollisionOption)	Task<StorageFile>	Saves a string value to a Windows.Storage.StorageFile in application local cache folder
WriteTextToLocalFileAsync(String, String, CreationCollisionOption)	Task<StorageFile>	Saves a string value to a Windows.Storage.StorageFile in application local folder

Sample Code

You can find more examples in our unit tests

Requirements

Device family	Universal, 10.0.16299.0 or higher
Namespace	Microsoft.Toolkit.Uwp
NuGet package	Microsoft.Toolkit.Uwp

API

• Storage File Helper source code