如何在运行时获取父类 [英] How to get the parent class at runtime

问题描述

是否可以在运行时获取 TypeScript 类的父类?我的意思是，例如，在装饰器中:

Is it possible to get the parent class of a TypeScript class at runtime? I mean, for example, within a decorator:

export function CustomDecorator(data: any) {
  return function (target: Function) {
    var parentTarget = ?
  }
}

我的自定义装饰器是这样应用的:

My custom decorator is applied this way:

export class AbstractClass {
  (...)
}

@CustomDecorator({
  (...)
})
export class SubClass extends AbstractClass {
  (...)
}

在装饰器中，我想要一个 AbstractClass 的实例.

Within the decorator, I would like to have an instance to AbstractClass.

非常感谢您的帮助！

推荐答案

您可以使用 Object.getPrototypeOf 函数.

类似于:

class A {
    constructor() {}
}

class B extends A {
    constructor() {
        super();
    }
}

class C extends B {
    constructor() {
        super();
    }
}

var a = new A();
var b = new B();
var c = new C();

Object.getPrototypeOf(a); // returns Object {}
Object.getPrototypeOf(b); // returns A {}
Object.getPrototypeOf(c); // returns B {}

---

编辑

代码后@DavidSherret 补充说(在评论中)，这就是你想要的(我认为):

---

Edit

After the code @DavidSherret added (in a comment), here's what you want (I think):

export function CustomDecorator(data: any) {
  return function (target: Function) {
    var parentTarget = target.prototype;
    ...
  }
}

或者正如@DavidSherret 指出的那样:

Or as @DavidSherret noted:

function CustomDecorator(data: any) {
  return function (target: Function) {
    console.log(Object.getPrototypeOf(new (target as any)));
  }
}

---

第二次编辑

好的，这就是我希望成为你的目标:

---

2nd Edit

Ok, so here's what I hope to be you goal:

function CustomDecorator(data: any) {
    return function (target: Function) {
        var parentTarget = Object.getPrototypeOf(target.prototype).constructor;
        console.log(parentTarget === AbstractClass); // true :)
    }
}

这篇关于如何在运行时获取父类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！