用于开放通用的Autofac注册提供者

Question

I have two implementations of a generic interface.

public class ConcreteComponent1<T>:IService<T>{}
public class ConcreteComponent2<T>:IService<T>{}

I have a factory which will create the proper concrete implementation.

public class ServiceFactory
{
    public IService<T> CreateService<T>()
    {
        //choose the right concrete component and create it
    }
}

I have a registered the below service consumer which will consume the service.

public class Consumer
{
    public Consumer(IService<Token> token){}    
}

I am not sure how to register a provider for open generic service with autofac. Any help appreciated. Thanks in advance.

Answer 1

As @Steven said I would also recommend against using a factory. Instead you could register your IService<T> as named or keyed service and then decide in the constructor of the Consumer class which implementation you want to use:

containerBuilder.RegisterGeneric(typeof(ConcreteComponent1<>)).Named("ConcreteComponent1", typeof(IService<>));
containerBuilder.RegisterGeneric(typeof(ConcreteComponent2<>)).Named("ConcreteComponent2", typeof(IService<>));
containerBuilder.RegisterType<Consumer>();

Then you can use the IIndex<K,V> class to get all the named implementations of your IService<T> class:

public class Consumer
{
    private readonly IService<Token> _token;

    public Consumer(IIndex<string, IService<Token>> tokenServices)
    {
        // select the correct service
        _token = tokenServices["ConcreteComponent1"];
    }
}

Alternatively if you don't want to name your services you can also get all available implementations by injecting IEnumerable<IService<Token>> and then choose the correct service however you like.