Casting SimpeInjectorWebApiDependencyRresolver to IDependencResolver

Question

I'm working on an ASP.Net web API project. Recently I've tried to refactor my solution and moving all the code relating to dependency injection to a separate project. I use Simple Injector Integration library as dependency injection solution. There is an IDependencyResolver interface in System.Web.Http.Dependencies which is implemented by SimpleInjectorWebApiDependencResolver. I created a class named ResolutionProvider which is supposed to provide a proper dependency resolver object for GlobalConfiguratiuon.Configuration.DependencyResolver field. The ResolutionProvider class has a method with the following signature and body:

public IDependencyResolver GetResolver()
{
    return new SimpleInjectorWebApiDependencyResolver(_container);
}

The problem is : However SimpleInjectorWebApiDependencyResolver implements IDependencyResolver, I'm getting a compile-time error: Cannot convert expression type SimpleInjectorWebApiDependencyResolver to retun type IDependencyResolver. I have tried to cast the class to its interface without no success.

Question:
What is the problem?

Answer 1

You should take a very good look at the compile error. The most likely cause is that the IDependencyResolver that your method returns is the System.Web.Mvc.IDependencyResolver and not the System.Web.Http.Dependencies.IDependencyResolver.