c# - .NET Core 中抽象类的依赖注入(inject)

Question

我不知道如何在抽象类中使用依赖注入(inject)。让我用一个简单的例子告诉你我的问题:

public abstract class Animal {

    public abstract void Move();

    public void Sleep() 
    {
        restService.StartSleeping(1000);    //how to get this service here?
    }
}

public class Cat : Animal
{
    public readonly IMotionService _motionService;    

    public Cat(IMotionService motionService)
    {
       _motionService = motionService;
    }

    public override void Move()
    {
        _motionService.Run();
    }
}

public class Bird : Animal
{
    public readonly IMotionService _motionService;    

    public Bird(IMotionService motionService)
    {
       _motionService = motionService;
    }

    public override void Move()
    {
        _motionService.Fly();
    }
}

每只动物都以不同的方式移动，所以 Move()函数在每个派生类中单独实现。正如您可能注意到的，整个实现来自 motionService .
另一方面，所有动物都以相同的方式 sleep ，所以我想把 Sleep()在基本抽象类中实现以避免重复代码，但我不能使用我的 restService与 Sleep实现，因为我不知道如何将服务类注入(inject)抽象类。
我想过IServiceProvider但它也应该注入(inject)。

Answer 1

你像这样传递它:

public abstract class Animal 
{
    private readonly IRestService restService;

    public Animal( IRestService restService )
    {
        this.restService = restService;
    }

    public abstract void Move();

    public void Sleep() 
    {
        restService.StartSleeping(1000);
    }
}

public class Cat : Animal
{
    // vv Should be private!
    public readonly IMotionService _motionService;    

    public Cat(IMotionService motionService, 
               IRestService restService)
            : base(restService) // pass on to base class ctor
    {
       _motionService = motionService;
    }

    public override void Move()
    {
        _motionService.Run();
    }
}

// Same in `Bird` class

供引用:Using Constructors (C# Programming Guide)