Resolving Generic Interface with Autofac

Question

Given the following code, how do I resolve the right SomeInstance in autofac?

public class BaseClass {}

public class SubClass1 : BaseClass {}

public class          


        

Answer 1

Correction. You cannot call MakeGenericType from the Container. I solved the issue of instantiating Generics using the 'TYPE' as the parameter on the Resolve call. The builder is registered.

        builder.RegisterGeneric(typeof (FakeRepository<>)).As(typeof (IRepository<>)).OnActivating(e =>
        {
            var typeToLookup = e.Parameters.FirstOrDefault() as TypedParameter;
            if (typeToLookup != null)
            {
                var respositoryType = typeof (FakeRepository<>);
                Type[] typeArgs = {typeToLookup.Value.GetType()};
                var genericType = respositoryType.MakeGenericType(typeArgs);
                var genericRepository = Activator.CreateInstance(genericType);
                e.ReplaceInstance(genericRepository);
            }
        });

Then the resolution happens like this, passing a TypedParameter to the Resolve. In this case I have a list of items (IItem) that are resolved that I want to create a repository for all of the items of that type.

        var items = container.Resolve>>();
        foreach (var item in items)
        {
            var repository = container.Resolve(typeof (IRepository), new TypedParameter(item.GetType(), item));
            Assert.IsNotNull(repository);
        }

Thanks for your post it helped and I Hope this update helps.