Covariance in Autofac?

I am using AutoFAC 2.2.4 and have a question about covariance in container resolution.

I have a base interface definition for my repositories:

IRepository<T, TKey>

Which has Find(Tkey), FindAll(), etc.

It is used, for example, like this:

IRepository<Catalog, int>

meaning a Catalog has an integer key. I registered its repository like this:

builder.RegisterType<CatalogRepository>()
    .As<IRepository<Catalog, int>>();

All was well. Later on I realized I needed an additional type of .Find() so I defiend a new interface:

ICatalogRepository : IRepository<Catalog, int>
{
    Catalog Find(string name);
}

And I changed the registeration:

builder.RegisterType<CatalogRepository>()
    .As<ICatalogRepository>();

But now attempts to resolve IRepository < Catalog, int > fail. I thought Autofac would recognize the relationship to ICatalogRepository and resolve it. I have had to do this:

builder.RegisterType<CatalogRepository>()
    .As<ICatalogRepository>()
    .As<IRepository<Catalog开发者_开发百科, int>>();

To get them both to resolve. (There are still calls to resolve IRepository from other generic entity manipulation tools that are unaware of the derived interface.) Am I doing something wrong?

That is the expected behavior. However, you can take a look at the assembly scanning feature and the AsImplementedInterfaces method in particular.