Implemented #2 - needs some updates, does not run with latest LTS ASP core 3.1

Author: tsv2013

Startup.cs

@@ -8,6 +8,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Hosting;
 
 namespace surveyjs_aspnet_mvc
 {
@@ -28,26 +29,30 @@ public void ConfigureServices(IServiceCollection services)
             // Adds a default in-memory implementation of IDistributedCache.
             services.AddDistributedMemoryCache();
 
-            services.AddSession(options =>
-            {
+            services.AddSession(options => {
                 // Set a short timeout for easy testing.
                 options.IdleTimeout = TimeSpan.FromSeconds(300);
                 options.Cookie.HttpOnly = true;
             });
+
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
-        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         {
-            if (env.IsDevelopment())
-            {
+            if (env.IsDevelopment()) {
                 app.UseDeveloperExceptionPage();
             }
 
             app.UseSession();
-            app.UseMvc();
+            app.UseRouting();
             app.UseDefaultFiles();
             app.UseStaticFiles();
+
+            app.UseEndpoints(endpoints => {
+                endpoints.MapControllers();
+            });
+
         }
     }
 }

surveyjs-aspnet-mvc.csproj

@@ -1,19 +1,15 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
     <Folder Include="wwwroot\" />
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.1.5" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.0" />
-  </ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.7" />
+</ItemGroup>
 
 </Project>