upgrades the main application to .net core 3.1

Tv7Playlist/Startup.cs

@@ -2,10 +2,10 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Tv7Playlist.Core;
 using Tv7Playlist.Core.Parsers;
@@ -43,11 +43,11 @@ namespace Tv7Playlist
             ConfigureParser(services, appConfig);
             ConfigureDatabase(services, appConfig);
 
-            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
+            services.AddRazorPages();
         }
 
         // 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())
             {
@@ -67,11 +67,12 @@ namespace Tv7Playlist
             app.UseStaticFiles();
             app.UseCookiePolicy();
 
-            app.UseMvc(routes =>
+            app.UseRouting();
+            app.UseEndpoints(endpoints =>
             {
-                routes.MapRoute(
-                    "default",
-                    "{controller=Home}/{action=Index}/{id?}");
+                endpoints.MapDefaultControllerRoute();
+                endpoints.MapControllers();
+                endpoints.MapRazorPages();
             });
         }