minor clean up in Startup and better error handling

samples/csharp_dotnetcore/05.multi-turn-prompt/Startup.cs

@@ -7,20 +7,12 @@
 using Microsoft.Bot.Builder;
 using Microsoft.Bot.Builder.Integration.AspNet.Core;
 using Microsoft.Bot.Connector.Authentication;
-using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.BotBuilderSamples
 {
     public class Startup
     {
-        public Startup(IConfiguration configuration)
-        {
-            Configuration = configuration;
-        }
-
-        public IConfiguration Configuration { get; }
-
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {

samples/csharp_dotnetcore/11.qnamaker/Startup.cs

@@ -13,10 +13,6 @@ namespace Microsoft.BotBuilderSamples
 {
     public class Startup
     {
-        public Startup()
-        {
-        }
-
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {

samples/csharp_dotnetcore/14.nlp-with-dispatch/Startup.cs

@@ -7,20 +7,12 @@
 using Microsoft.Bot.Builder;
 using Microsoft.Bot.Builder.Integration.AspNet.Core;
 using Microsoft.Bot.Connector.Authentication;
-using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.BotBuilderSamples
 {
     public class Startup
     {
-        public Startup(IConfiguration configuration)
-        {
-            Configuration = configuration;
-        }
-
-        public IConfiguration Configuration { get; }
-
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {

samples/csharp_dotnetcore/19.custom-dialogs/AdapterWithErrorHandler.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+using System;
+using Microsoft.Bot.Builder;
 using Microsoft.Bot.Builder.Integration.AspNet.Core;
 using Microsoft.Bot.Connector.Authentication;
 using Microsoft.Extensions.Logging;
@@ -9,14 +11,31 @@ namespace Microsoft.BotBuilderSamples
 {
     public class AdapterWithErrorHandler : BotFrameworkHttpAdapter
     {
-        public AdapterWithErrorHandler(ICredentialProvider credentialProvider, ILogger<BotFrameworkHttpAdapter> logger)
+        public AdapterWithErrorHandler(ICredentialProvider credentialProvider, ILogger<BotFrameworkHttpAdapter> logger, ConversationState conversationState = null)
             : base(credentialProvider)
         {
-            // Enable logging at the adapter level using OnTurnError.
             OnTurnError = async (turnContext, exception) =>
             {
-                logger.LogError($"Exception caught : {exception}");
+                // Log any leaked exception from the application.
+                logger.LogError($"Exception caught : {exception.Message}");
+
+                // Send a catch-all appology to the user.
                 await turnContext.SendActivityAsync("Sorry, it looks like something went wrong.");
+
+                if (conversationState != null)
+                {
+                    try
+                    {
+                        // Delete the conversationState for the current conversation to prevent the
+                        // bot from getting stuck in a error-loop caused by being in a bad state.
+                        // ConversationState should be thought of as similar to "cookie-state" in a Web pages.
+                        await conversationState.DeleteAsync(turnContext);
+                    }
+                    catch (Exception e)
+                    {
+                        logger.LogError($"Exception caught on attempting to Delete ConversationState : {e.Message}");
+                    }
+                }
             };
         }
     }

samples/csharp_dotnetcore/19.custom-dialogs/Startup.cs

@@ -14,13 +14,6 @@ namespace Microsoft.BotBuilderSamples
 {
     public class Startup
     {
-        public Startup(IConfiguration configuration)
-        {
-            Configuration = configuration;
-        }
-
-        public IConfiguration Configuration { get; }
-
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {

samples/csharp_dotnetcore/42.scaleout/Startup.cs

@@ -7,20 +7,12 @@
 using Microsoft.Bot.Builder;
 using Microsoft.Bot.Builder.Integration.AspNet.Core;
 using Microsoft.Bot.Connector.Authentication;
-using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.BotBuilderSamples
 {
     public class Startup
     {
-        public Startup(IConfiguration configuration)
-        {
-            Configuration = configuration;
-        }
-
-        public IConfiguration Configuration { get; }
-
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {