依赖注入：注入泛型接口的 IEnumerable<I<Base>>

Question

我想注入通用接口的

IEnumerable

。
使用

Microsoft.Extensions.DependencyInjection

可以实现吗？

这对于协变和逆变都不起作用。零实现被注入到

ConcreteClassFactory

。有什么办法可以做到吗？

public interface IGenericInterface<T>
{
    void Do(T obj);
}

public abstract class Animal
{
}

public class Dog : Animal
{
}

public class Cat : Animal
{
}

public class ConcreteClassA : IGenericInterface<Dog>
{
    public void Do(Dog obj)
    {
        throw new NotImplementedException();
    }
}

public class ConcreteClassB : IGenericInterface<Cat>
{
    public void Do(Cat obj)
    {
        throw new NotImplementedException();
    }
}


public class ConcreteClassFactory
{
    public ConcreteClassFactory(IEnumerable<IGenericInterface<Animal>> concretes)
    {
    }
}

服务注册：

builder.Services
         .AddSingleton<IGenericInterface<Cat>, ConcreteClassB>()
         .AddSingleton<IGenericInterface<Dog>, ConcreteClassA>()
         .AddSingleton<ConcreteClassFactory>();

Answer 1

是的，通过依赖注入，您可以创建一个两个泛型接口都可以实现的非泛型接口：

public interface IGenericInterface<T> {
    void Do(T obj);
}

public interface INonGenericInterface {
    void Do(object obj);
}

// your three Animal classes

public class ConcreteClassA : IGenericInterface<Dog>, INonGenericInterface
{
    public void Do(Dog obj)
    {
        throw new NotImplementedException();
    }

    public void Do(object obj)
    {
        Do((Dog)obj);
    }
}

public class ConcreteClassB : IGenericInterface<Cat>, INonGenericInterface
{
    public void Do(Cat obj)
    {
        throw new NotImplementedException();
    }

    public void Do(object obj)
    {
        Do((Cat)obj);
    }
}

public class ConcreteClassFactory {
    public ConcreteClassFactory(IEnumerable<INonGenericInterface> concretes)
    {
        foreach (var concrete in concretes)
        {
            // Perform initialization or registration
        }
    }
}

服务注册：

builder.Services
    .AddSingleton<IGenericInterface<Cat>, ConcreteClassB>()
    .AddSingleton<IGenericInterface<Dog>, ConcreteClassA>()
    .AddSingleton<INonGenericInterface, ConcreteClassB>()
    .AddSingleton<INonGenericInterface, ConcreteClassA>()
    .AddSingleton<ConcreteClassFactory>();