Update .NET Core sample to 3.1 (reactjs#1020)

* Update .NET Core sample to 3.1

* Update azure-pipelines.yml

* Update azure-pipelines.yml

* Update global.json

Author: dustinsoftware

azure-pipelines.yml

@@ -19,7 +19,7 @@ steps:
     - task: DotNetCoreInstaller@0
       inputs:
         packageType: 'sdk'
-        version: '3.0.100'
+        version: '3.1.100'
 
     - task: VSBuild@1
       inputs:

global.json

@@ -1,6 +1,6 @@
 {
   "projects": [ "src", "test" ],
   "sdk": {
-    "version": "3.0.100-preview"
+    "version": "3.1.100"
   }
 }

src/React.Sample.Webpack.CoreMvc/React.Sample.Webpack.CoreMvc.csproj

@@ -1,12 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.2;netcoreapp3.0</TargetFrameworks>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Folder Include="wwwroot\" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.2' ">
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.1' ">
     <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.2.0" />
     <PackageReference Include="Microsoft.NET.Sdk.Razor" Version="2.2.0" />

src/React.Sample.Webpack.CoreMvc/Startup.cs

@@ -1,8 +1,6 @@
-using System;
 using JavaScriptEngineSwitcher.ChakraCore;
 using JavaScriptEngineSwitcher.Extensions.MsDependencyInjection;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
@@ -51,7 +49,6 @@ public void Configure(IApplicationBuilder app)
 
 			app.UseStaticFiles();
 
-#if NETCOREAPP3_0
 			app.UseRouting();
 
 			app.UseEndpoints(endpoints =>
@@ -60,14 +57,6 @@ public void Configure(IApplicationBuilder app)
 				endpoints.MapControllerRoute("comments-root", "comments", new { controller = "Home", action = "Index" });
 				endpoints.MapControllerRoute("comments", "comments/page-{page}", new { controller = "Home", action = "Comments" });
 			});
-#else
-			app.UseMvc(routes =>
-			{
-				routes.MapRoute("default", "{path?}", new { controller = "Home", action = "Index" });
-				routes.MapRoute("comments-root", "comments", new { controller = "Home", action = "Index" });
-				routes.MapRoute("comments", "comments/page-{page}", new { controller = "Home", action = "Comments" });
-			});
-#endif
 		}
 	}
 }