Razor file compilation (#17709)

* Razor file compilation

* Razor file compilation

* Razor file compilation

* Razor file compilation

* Apply suggestions from code review

Co-Authored-By: Scott Addie <10702007+scottaddie@users.noreply.github.com>

* Razor file compilation

* Razor file compilation

Co-authored-by: Scott Addie <10702007+scottaddie@users.noreply.github.com>

Author: Rick-Anderson

aspnetcore/mvc/views/view-compilation.md

@@ -25,7 +25,7 @@ To enable runtime compilation for all environments and configuration modes:
 
 1. Install the [Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation](https://www.nuget.org/packages/Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation/) NuGet package.
 
-1. Update the project's `Startup.ConfigureServices` method to include a call to `AddRazorRuntimeCompilation`. For example:
+1. Update the project's `Startup.ConfigureServices` method to include a call to <xref:Microsoft.Extensions.DependencyInjection.RazorRuntimeCompilationMvcBuilderExtensions.AddRazorRuntimeCompilation*>. For example:
 
     ```csharp
     public void ConfigureServices(IServiceCollection services)
@@ -55,29 +55,15 @@ To enable runtime compilation based on the environment and configuration mode:
 
 1. Update the project's `Startup.ConfigureServices` method to include a call to `AddRazorRuntimeCompilation`. Conditionally execute `AddRazorRuntimeCompilation` such that it only runs in Debug mode when the `ASPNETCORE_ENVIRONMENT` variable is set to `Development`:
 
-    ```csharp
-    public IWebHostEnvironment Env { get; set; }
-
-    public void ConfigureServices(IServiceCollection services)
-    {
-        IMvcBuilder builder = services.AddRazorPages();
-
-    #if DEBUG
-        if (Env.IsDevelopment())
-        {
-            builder.AddRazorRuntimeCompilation();
-        }
-    #endif
-
-        // code omitted for brevity
-    }
-    ```
+  [!code-csharp[](~/mvc/views/view-compilation/sample/Startup.cs?name=snippet)]
 
 ## Additional resources
 
+* [RazorCompileOnBuild and RazorCompileOnPublish](xref:razor-pages/sdk#properties) properties.
 * <xref:razor-pages/index>
 * <xref:mvc/views/overview>
 * <xref:razor-pages/sdk>
+* See the [runtimecompilation sample on GitHub](https://github.com/aspnet/samples/tree/master/samples/aspnetcore/mvc/runtimecompilation) for a sample that shows making runtime compilation work across projects.
 
 ::: moniker-end
 
@@ -104,4 +90,4 @@ Build-time compilation is supplemented by runtime compilation of Razor files. AS
 * <xref:mvc/views/overview>
 * <xref:razor-pages/sdk>
 
-::: moniker-end
+::: moniker-end

aspnetcore/mvc/views/view-compilation/sample/Startup.cs

@@ -0,0 +1,56 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+#region snippet
+public class Startup
+{
+    public Startup(IConfiguration configuration, IWebHostEnvironment env)
+    {
+        Configuration = configuration;
+        Env = env;
+    }
+
+    public IWebHostEnvironment Env { get; set; }
+    public IConfiguration Configuration { get; }
+
+    public void ConfigureServices(IServiceCollection services)
+    {
+        IMvcBuilder builder = services.AddRazorPages();
+
+#if DEBUG
+            if (Env.IsDevelopment())
+            {
+                builder.AddRazorRuntimeCompilation();
+            }
+#endif
+    }
+
+    public void Configure(IApplicationBuilder app)
+    {
+        if (Env.IsDevelopment())
+        {
+            app.UseDeveloperExceptionPage();
+        }
+        else
+        {
+            app.UseExceptionHandler("/Error");
+            app.UseHsts();
+        }
+
+        app.UseHttpsRedirection();
+        app.UseStaticFiles();
+
+        app.UseRouting();
+
+        app.UseAuthorization();
+
+        app.UseEndpoints(endpoints =>
+        {
+            endpoints.MapRazorPages();
+        });
+    }
+}
+#endregion