drop Accessors class

samples/csharp_dotnetcore/03.welcome-user/WelcomeUserBot.cs

@@ -2,7 +2,6 @@
 // Licensed under the MIT License.
 
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Bot.Builder;
@@ -39,16 +38,12 @@ of the 'ConversationUpdate' event depends on the channel. You can
                                               to user, explaining what your bot can do. In this example, the bot
                                               handles 'hello', 'hi', 'help' and 'intro. Try it now, type 'hi'";
 
-        // The bot state accessor object. Use this to access specific state properties.
-        private WelcomeUserStateAccessors _welcomeUserStateAccessors;
-        private UserState _userState;
+        private BotState _userState;
 
         // Initializes a new instance of the "WelcomeUserBot" class. 
         public WelcomeUserBot(UserState userState)
         {
             _userState = userState;
-            _welcomeUserStateAccessors = new WelcomeUserStateAccessors(userState);
-            _welcomeUserStateAccessors.WelcomeUserState = _userState.CreateProperty<WelcomeUserState>(WelcomeUserStateAccessors.WelcomeUserName); 
         }
 
 
@@ -72,16 +67,12 @@ protected override async Task OnMembersAddedAsync(IList<ChannelAccount> membersA
 
         protected override async Task OnMessageActivityAsync(ITurnContext<IMessageActivity> turnContext, CancellationToken cancellationToken)
         {
-            var didBotWelcomeUser = await _welcomeUserStateAccessors.WelcomeUserState.GetAsync(turnContext, () => new WelcomeUserState());
-
-            WelcomeUserState welcomeUserState = await _welcomeUserStateAccessors.WelcomeUserState.GetAsync(turnContext, () => new WelcomeUserState());
+            var welcomeUserStateAccessor = _userState.CreateProperty<WelcomeUserState>(nameof(WelcomeUserState));
+            var didBotWelcomeUser = await welcomeUserStateAccessor.GetAsync(turnContext, () => new WelcomeUserState());
 
             if (didBotWelcomeUser.DidBotWelcomeUser == false)
             {
                 didBotWelcomeUser.DidBotWelcomeUser = true;
-                // Update user state flag to reflect bot handled first user interaction.
-                await _welcomeUserStateAccessors.WelcomeUserState.SetAsync(turnContext, didBotWelcomeUser);
-                await _welcomeUserStateAccessors.UserState.SaveChangesAsync(turnContext);
 
                 // the channel should sends the user name in the 'From' object
                 var userName = turnContext.Activity.From.Name;
@@ -108,7 +99,9 @@ protected override async Task OnMessageActivityAsync(ITurnContext<IMessageActivi
                         break;
                 }
             }
-            await _welcomeUserStateAccessors.UserState.SaveChangesAsync(turnContext);
+
+            // Save any state changes.
+            await _userState.SaveChangesAsync(turnContext);
         }
 
         private static async Task SendIntroCardAsync(ITurnContext turnContext, CancellationToken cancellationToken)