Interface method that receives a parameter of type of class that inherited it

问题

I' trying to make something like this:

public interface ICar
{
    public void Update(/*something here*/);
}

Then two classes:

public class Peugeot : ICar
{
    public void Update(Peugeot car)
    {

    }
}

public class Volvo : ICar
{
    public void Update(Volvo car)
    {

    }
}

How can I achieve this?

回答1:

You could make ICar generic:

public interface ICar<T> where T : ICar<T>
{
    public void Update<T>(T car);
}

And then implement the Update methods accordingly:

public class Peugeot : ICar<Peugeot>
{
    public void Update(Peugeot car)
    {

    }
}

public class Volvo : ICar<Volvo>
{
    public void Update(Volvo car)
    {

    }
}

回答2:

You can (at least sort of) achieve this by making an explicit interface implementation, and then providing a public Update method that is properly typed:

public interface ICar
{
    void Update(ICar car);
}

public class Peugeot : ICar
{
    public void Update(Peugeot car)
    {
        Update(car);
    }

    void ICar.Update(ICar car)
    {
        // do some updating
    }
}

public class Volvo : ICar
{
    public void Update(Volvo car)
    {
        Update(car);
    }

    void ICar.Update(ICar car)
    {
        // do some updating
    }
}

来源：https://stackoverflow.com/questions/21186347/interface-method-that-receives-a-parameter-of-type-of-class-that-inherited-it