asp.net-mvc – 该类型不能分配给服务autofac

public interface ICategoryFacade
{
    IEnumerable<Category> Get();
    Category Get(int id);
    int Post(Category model);
    int Put(Category model);
    int Patch(Category model);
    int Delete(int id);

}

我上课了：

public class CategoryFacade : ICategoryFacade
{
    MyContext _dbContext = new MyContext ();

    public IEnumerable<Category> Get()
    {
        return _dbContext.Categories;
    }
    public Category Get(int id)
    {
        return _dbContext.Categories.FirstOrDefault(m => m.CategoryID == id);
    }
    public int Post(Category model)
    {
        return 0;
    }
    public int Put(Category model)
    {
        return 0;
    }
    public int Patch(Category model)
    {
        return 0;
    }
    public int Delete(int id)
    {
        return 0;
    }
}

现在我想将IOC与我的ODATA控制器一起使用.所以为了做到这一点,我在Global.asax文件中使用以下代码行(Application_Start事件)：

var builder = new ContainerBuilder();
        builder.RegisterApiControllers(Assembly.GetExecutingAssembly());

        builder.RegisterInstance(new CategoryFacade()).As<ICategoryFacade>();
        builder.RegisterInstance(new TVideoFacade()).As<ITVideoFacade>();

        builder.RegisterType<CategoryController>();


        //builder.RegisterType<CategoryFacade>().As<ICategoryFacade>();
        //builder.RegisterType<TVideoFacade>().As<ITVideoFacade>();

        //builder.Register(c => new CategoryFacade()).As<ICategoryFacade>().InstancePerRequest();
        //builder.Register(c => new TVideoFacade()).As<ITVideoFacade>().InstancePerRequest();

        var container = builder.Build();
        var resolver = new AutofacWebApiDependencyResolver(container);
        GlobalConfiguration.Configuration.DependencyResolver = resolver;

但它显示以下异常：

Additional information: The type 'ABC.ABCDatabase.Facades.TVideoFacade' is not assignable to service 'ABC.ABCDatabase.Abstractions.ICategoryFacade'.

你能告诉我在OData控制器上使用autofac的正确方法吗？我是autofac的新手.