根据子类从基类指定抽象方法的返回类型 [英] Specifying the return type of an abstract method from a Base Class according to a Sub Class

问题描述

我有以下结构:

abstract class Base {
        public abstract List<...> Get(); //What should be the generic type?
}

class SubOne : Base {
    public override List<SubOne> Get() {

    }
}

class SubTwo : Base {
    public override List<SubTwo> Get() {

    }
}

我想创建一个抽象方法，该方法返回具体子类是什么类.因此，从示例中可以看出，SubOne 中的方法应该返回 List 而 SubTwo 中的方法应该返回 List.

I want to create an abstract method that returns whatever class the concrete sub class is. So, as you can see from the example, the method in SubOne should return List<SubOne> whereas the method in SubTwo should return List<SubTwo>.

我在基类中声明的签名中指定什么类型?

What type do I specify in the signature declared in the Base class ?

[更新]

感谢您发布的答案.

解决方案是使抽象类具有通用性，例如:

The solution is to make the abstract class generic, like such:

abstract class Base<T> {
        public abstract List<T> Get();
}

class SubOne : Base<SubOne> {
    public override List<SubOne> Get() {

    }
}

class SubTwo : Base<SubTwo> {
    public override List<SubTwo> Get() {

    }
} 

推荐答案

你的抽象类应该是通用的.

Your abstract class should be generic.

abstract class Base<T> {
        public abstract List<T> Get(); 
}

class SubOne : Base<SubOne> {
    public override List<SubOne> Get() {

    }
}

class SubTwo : Base<SubTwo> {
    public override List<SubTwo> Get() {
    }
}

如果需要引用没有泛型类型参数的抽象类，请使用接口:

If you need to refer to the abstract class without the generic type argument, use an interface:

interface IBase {
        //common functions
}

abstract class Base<T> : IBase {
        public abstract List<T> Get(); 
}

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