Inject WebAPI UrlHelper into service using Autofac

Question

I have a service used by a few controllers in my WebAPI project. The service needs to generate URLs, so ideally it would get a UrlHelper via a constructor parameter

Answer 1

Use the RegisterHttpRequestMessage method to register the current request and then you can also register the URL helper like so:

public static IContainer SetupContainer(HttpConfiguration config)
{
    var containerBuilder = new ContainerBuilder();

    // Register your Web API.
    containerBuilder.RegisterApiControllers(Assembly.GetExecutingAssembly());
    containerBuilder.RegisterHttpRequestMessage(config);
    containerBuilder.Register(x => new UrlHelper(x.Resolve()));  
    containerBuilder.RegisterWebApiFilterProvider(config);
    containerBuilder.RegisterWebApiModelBinderProvider();

    // Register your other types...

    var container = containerBuilder.Build();

    // Set the dependency resolver to be Autofac.
    config.DependencyResolver = new AutofacWebApiDependencyResolver(container);

    return container;
}