Autofac：注册显式通用接口

Question

With Autofac, i can register a generic interface like this:

builder.RegisterType<MyService<MyViewModel>>().As<IMyService<MyViewModel>>();

is it possible to register like this instead?

builder.RegisterType<MyService<MyViewModel>>().As<IMyService<IMyViewModel>>();

Answer 1

Yes. It is possible but you need to add generic constraint and out (generic modifier).

Here is an example.

public interface IMyService<out TModel>
    where TModel : IMyViewModel
{
}

public class MyService<TModel> : IMyService<TModel>
    where TModel : IMyViewModel
{
}

public interface IMyViewModel
{
}

public class MyViewModel : IMyViewModel
{
}

// Register
builder.RegisterType<MyService<MyViewModel>>().As<IMyService<MyViewModel>>();
builder.RegisterType<MyService<MyViewModel>>().As<IMyService<IMyViewModel>>();

// Resovle
var resolve1 = container.Resolve<IMyService<MyViewModel>>();
var resolve2 = container.Resolve<IMyService<IMyViewModel>>();