ASP.NET Core Blazor uses the generic app hosting in ASP.NET Core 3+ but the two hosting models have slightly different integrations.

Server-side implementations are configured in exactly the same way as any other ASP.NET Core 3 application.

Client-side injection is slightly more restricted due to requirements for WebAssembly hosting.

At present (as of 11/9/2019), some of the features around Startup classes are not available: ConfiguresServices and ConfigureContainer will not be executed by UseBlazorStartup.

The alternative is to use UseServiceProviderFactory with an instance of AutofacServiceProviderFactory. The AutofacServiceProviderFactory takes an Action on a ContainerBuilder which can be used for any registrations.


public class Program
  public static void Main(string[] args)

  public static IWebAssemblyHostBuilder CreateHostBuilder(string[] args) =>
      .UseServiceProviderFactory(new AutofacServiceProviderFactory(Register))

  private static void Register(ContainerBuilder builder)
    // add any registrations here

Once registered, Blazor components can use dependency injection via the standard @inject Razor directive.