Replace WebHostBuilder with HostBuilder pattern in MVC folder

src/Hosting/Hosting/src/GenericHost/GenericWebHostBuilder.cs

@@ -20,7 +20,7 @@ namespace Microsoft.AspNetCore.Hosting;
 
 internal sealed class GenericWebHostBuilder : WebHostBuilderBase, ISupportsStartup
 {
-    private object? _startupObject;
+    private const string _startupConfigName = "__UseStartup.StartupType";
     private readonly object _startupKey = new object();
 
     private AggregateException? _hostingStartupErrors;
@@ -170,12 +170,13 @@ public IWebHostBuilder UseStartup([DynamicallyAccessedMembers(StartupLinkerOptio
         UseSetting(WebHostDefaults.ApplicationKey, startupAssemblyName);
 
         // UseStartup can be called multiple times. Only run the last one.
-        _startupObject = startupType;
+        _builder.Properties[_startupConfigName] = startupType;
 
         _builder.ConfigureServices((context, services) =>
         {
             // Run this delegate if the startup type matches
-            if (object.ReferenceEquals(_startupObject, startupType))
+            if (_builder.Properties.TryGetValue(_startupConfigName, out var startupObject) &&
+                object.ReferenceEquals(startupObject, startupType))
             {
                 UseStartup(startupType, context, services);
             }
@@ -193,15 +194,16 @@ public IWebHostBuilder UseStartup([DynamicallyAccessedMembers(StartupLinkerOptio
         UseSetting(WebHostDefaults.ApplicationKey, startupAssemblyName);
 
         // Clear the startup type
-        _startupObject = startupFactory;
+        _builder.Properties[_startupConfigName] = startupFactory;
 
         _builder.ConfigureServices(ConfigureStartup);
 
         [UnconditionalSuppressMessage("Trimmer", "IL2072", Justification = "Startup type created by factory can't be determined statically.")]
         void ConfigureStartup(HostBuilderContext context, IServiceCollection services)
         {
             // UseStartup can be called multiple times. Only run the last one.
-            if (object.ReferenceEquals(_startupObject, startupFactory))
+            if (_builder.Properties.TryGetValue(_startupConfigName, out var startupObject) &&
+                object.ReferenceEquals(startupObject, startupFactory))
             {
                 var webHostBuilderContext = GetWebHostBuilderContext(context);
                 var instance = startupFactory(webHostBuilderContext) ?? throw new InvalidOperationException("The specified factory returned null startup instance.");
@@ -316,11 +318,12 @@ public IWebHostBuilder Configure(Action<IApplicationBuilder> configure)
         UseSetting(WebHostDefaults.ApplicationKey, startupAssemblyName);
 
         // Clear the startup type
-        _startupObject = configure;
+        _builder.Properties[_startupConfigName] = configure;
 
         _builder.ConfigureServices((context, services) =>
         {
-            if (object.ReferenceEquals(_startupObject, configure))
+            if (_builder.Properties.TryGetValue(_startupConfigName, out var startupObject) &&
+                object.ReferenceEquals(startupObject, configure))
             {
                 services.Configure<GenericWebHostServiceOptions>(options =>
                 {
@@ -339,11 +342,12 @@ public IWebHostBuilder Configure(Action<WebHostBuilderContext, IApplicationBuild
         UseSetting(WebHostDefaults.ApplicationKey, startupAssemblyName);
 
         // Clear the startup type
-        _startupObject = configure;
+        _builder.Properties[_startupConfigName] = configure;
 
         _builder.ConfigureServices((context, services) =>
         {
-            if (object.ReferenceEquals(_startupObject, configure))
+            if (_builder.Properties.TryGetValue(_startupConfigName, out var startupObject) &&
+                object.ReferenceEquals(startupObject, configure))
             {
                 services.Configure<GenericWebHostServiceOptions>(options =>
                 {

src/Mvc/perf/benchmarkapps/BasicApi/Startup.cs

@@ -11,6 +11,7 @@
 using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Migrations;
@@ -229,25 +230,29 @@ private void DropDatabaseTables(IServiceProvider services)
 
         public static void Main(string[] args)
         {
-            var host = CreateWebHostBuilder(args)
+            using var host = CreateHost(args)
                 .Build();
 
             host.Run();
         }
 
-        public static IWebHostBuilder CreateWebHostBuilder(string[] args)
+        public static IHostBuilder CreateHost(string[] args)
         {
             var configuration = new ConfigurationBuilder()
                 .AddEnvironmentVariables()
                 .AddCommandLine(args)
                 .Build();
 
-            return new WebHostBuilder()
-                .UseKestrel()
-                .UseUrls("http://+:5000")
-                .UseConfiguration(configuration)
-                .UseContentRoot(Directory.GetCurrentDirectory())
-                .UseStartup<Startup>();
+            return new HostBuilder()
+                .ConfigureWebHost(webHostBuilder =>
+                {
+                    webHostBuilder
+                        .UseKestrel()
+                        .UseUrls("http://+:5000")
+                        .UseConfiguration(configuration)
+                        .UseContentRoot(Directory.GetCurrentDirectory())
+                        .UseStartup<Startup>();
+                });
         }
     }
 }

src/Mvc/perf/benchmarkapps/BasicViews/Startup.cs

@@ -8,6 +8,7 @@
 #endif
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Migrations;
@@ -191,26 +192,30 @@ private void DropDatabaseTables(IServiceProvider services)
 
         public static void Main(string[] args)
         {
-            var host = CreateWebHostBuilder(args)
+            using var host = CreateHost(args)
                 .Build();
 
             host.Run();
         }
 
-        public static IWebHostBuilder CreateWebHostBuilder(string[] args)
+        public static IHostBuilder CreateHost(string[] args)
         {
             var configuration = new ConfigurationBuilder()
                 .AddEnvironmentVariables()
                 .AddCommandLine(args)
                 .Build();
 
-            return new WebHostBuilder()
-                .UseKestrel()
-                .UseUrls("http://+:5000")
-                .UseConfiguration(configuration)
-                .UseIISIntegration()
-                .UseContentRoot(Directory.GetCurrentDirectory())
-                .UseStartup<Startup>();
+            return new HostBuilder()
+                .ConfigureWebHost(webHostBuilder =>
+                {
+                    webHostBuilder
+                        .UseKestrel()
+                        .UseUrls("http://+:5000")
+                        .UseConfiguration(configuration)
+                        .UseIISIntegration()
+                        .UseContentRoot(Directory.GetCurrentDirectory())
+                        .UseStartup<Startup>();
+                });
         }
     }
 }

src/Mvc/perf/benchmarkapps/RazorRendering/Startup.cs

@@ -4,6 +4,7 @@
 using Data;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.AspNetCore.Html;
@@ -60,24 +61,28 @@ private static List<DataB> GenerateDataB()
 
     public static void Main(string[] args)
     {
-        var host = CreateWebHostBuilder(args)
+        using var host = CreateHost(args)
             .Build();
 
         host.Run();
     }
 
-    public static IWebHostBuilder CreateWebHostBuilder(string[] args)
+    public static IHostBuilder CreateHost(string[] args)
     {
         var configuration = new ConfigurationBuilder()
             .AddEnvironmentVariables()
             .AddCommandLine(args)
             .Build();
 
-        return new WebHostBuilder()
-            .UseKestrel()
-            .UseUrls("http://+:5000")
-            .UseConfiguration(configuration)
-            .UseContentRoot(Directory.GetCurrentDirectory())
-            .UseStartup<Startup>();
+        return new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseKestrel()
+                    .UseUrls("http://+:5000")
+                    .UseConfiguration(configuration)
+                    .UseContentRoot(Directory.GetCurrentDirectory())
+                    .UseStartup<Startup>();
+            });
     }
 }

src/Mvc/samples/MvcSandbox/Startup.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using Microsoft.Extensions.Hosting;
+
 namespace MvcSandbox;
 
 public class Startup
@@ -42,22 +44,26 @@ static void ConfigureEndpoints(IEndpointRouteBuilder endpoints)
 
     public static void Main(string[] args)
     {
-        var host = CreateWebHostBuilder(args)
+        using var host = CreateHostBuilder(args)
             .Build();
 
         host.Run();
     }
 
-    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
-        new WebHostBuilder()
-            .UseContentRoot(Directory.GetCurrentDirectory())
-            .ConfigureLogging(factory =>
+    public static IHostBuilder CreateHostBuilder(string[] args) =>
+        new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
             {
-                factory
-                    .AddConsole()
-                    .AddDebug();
-            })
-            .UseKestrel()
-            .UseStartup<Startup>();
+                webHostBuilder
+                    .UseContentRoot(Directory.GetCurrentDirectory())
+                    .ConfigureLogging(factory =>
+                    {
+                        factory
+                            .AddConsole()
+                            .AddDebug();
+                    })
+                    .UseKestrel()
+                    .UseStartup<Startup>();
+            });
 }
 

src/Mvc/test/WebSites/ApiExplorerWebSite/Startup.cs

@@ -4,6 +4,7 @@
 using ApiExplorerWebSite.Controllers;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.AspNetCore.Mvc.Infrastructure;
+using Microsoft.Extensions.Hosting;
 
 namespace ApiExplorerWebSite;
 
@@ -45,17 +46,21 @@ public void Configure(IApplicationBuilder app)
 
     public static void Main(string[] args)
     {
-        var host = CreateWebHostBuilder(args)
+        using var host = CreateHostBuilder(args)
             .Build();
 
         host.Run();
     }
 
-    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
-        new WebHostBuilder()
-            .UseContentRoot(Directory.GetCurrentDirectory())
-            .UseKestrel()
-            .UseIISIntegration()
-            .UseStartup<Startup>();
+    public static IHostBuilder CreateHostBuilder(string[] args) =>
+        new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseContentRoot(Directory.GetCurrentDirectory())
+                    .UseKestrel()
+                    .UseIISIntegration()
+                    .UseStartup<Startup>();
+            });
 }
 

src/Mvc/test/WebSites/ApplicationModelWebSite/Startup.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using Microsoft.Extensions.Hosting;
+
 namespace ApplicationModelWebSite;
 
 public class Startup
@@ -34,17 +36,21 @@ public void Configure(IApplicationBuilder app)
 
     public static void Main(string[] args)
     {
-        var host = CreateWebHostBuilder(args)
+        using var host = CreateHostBuilder(args)
             .Build();
 
         host.Run();
     }
 
-    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
-        new WebHostBuilder()
-            .UseContentRoot(Directory.GetCurrentDirectory())
-            .UseStartup<Startup>()
-            .UseKestrel()
-            .UseIISIntegration();
+    public static IHostBuilder CreateHostBuilder(string[] args) =>
+        new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseContentRoot(Directory.GetCurrentDirectory())
+                    .UseStartup<Startup>()
+                    .UseKestrel()
+                    .UseIISIntegration();
+            });
 }
 

src/Mvc/test/WebSites/BasicWebSite/Program.cs

@@ -1,20 +1,29 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using Microsoft.Extensions.Hosting;
+
 namespace BasicWebSite;
 
 public class Program
 {
-    public static void Main(string[] args) => CreateWebHostBuilder(args).Build().Run();
+    public static void Main(string[] args)
+    {
+        using var host = CreateHostBuilder(args).Build();
+        host.Run();
+    }
 
-    // Do not change. This is the pattern our test infrastructure uses to initialize a IWebHostBuilder from
-    // a users app.
-    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
-        new WebHostBuilder()
-            .UseContentRoot(Directory.GetCurrentDirectory())
-            .UseStartup<StartupWithoutEndpointRouting>()
-            .UseKestrel()
-            .UseIISIntegration();
+    // This method now returns IHostBuilder and uses the new pattern with HostBuilder and ConfigureWebHost
+    public static IHostBuilder CreateHostBuilder(string[] args) =>
+        new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseContentRoot(Directory.GetCurrentDirectory())
+                    .UseStartup<StartupWithoutEndpointRouting>()
+                    .UseKestrel()
+                    .UseIISIntegration();
+            });
 }
 
 public class TestService