我尝试创建一个通用的复制/克隆服务，为嵌套对象保留类型。会爱反馈，如果我做错了什么，但它似乎工作到目前为止…

import { Injectable } from '@angular/core';

@Injectable()
export class CopyService {

  public deepCopy<T>(objectToClone: T): T {
    // If it's a simple type or null, just return it.
    if (typeof objectToClone === 'string' ||
      typeof objectToClone === 'number' ||
      typeof objectToClone === 'undefined' ||
      typeof objectToClone === 'symbol' ||
      typeof objectToClone === 'function' ||
      typeof objectToClone === 'boolean' ||
      objectToClone === null
    ) {
      return objectToClone;
    }

    // Otherwise, check if it has a constructor we can use to properly instantiate it...
    let ctor = Object.getPrototypeOf(objectToClone).constructor;
    if (ctor) {
      let clone = new ctor();

      // Once we've instantiated the correct type, assign the child properties with deep copies of the values
      Object.keys(objectToClone).forEach(key => {
        if (Array.isArray(objectToClone[key]))
          clone[key] = objectToClone[key].map(item => this.deepCopy(item));
        else
          clone[key] = this.deepCopy(objectToClone[key]);
      });

      if (JSON.stringify(objectToClone) !== JSON.stringify(clone))
        console.warn('object cloned, but doesnt match exactly...\nobject: ' + JSON.stringify(objectToClone) + "\nclone: " + JSON.stringify(clone))

      // return our cloned object...
      return clone;
    }
    else {
      //not sure this will ever get hit, but figured I'd have a catch call.
      console.log('deep copy found something it didnt know: ' + JSON.stringify(objectToClone));
      return objectToClone;
    }
  }
}

如果你已经有了目标对象，所以你不想重新创建它(就像更新一个数组一样)，你必须复制属性。 如果这样做:

Object.keys(source).forEach((key) => {
    copy[key] = source[key]
})

赞美是应得的。(请看标题“版本2”)

如果还想复制方法，而不仅仅是复制数据，请遵循此方法

let copy = new BaseLayer() ;
Object.assign(copy, origin);
copy.x = 8 ; //will not affect the origin object

只需将BaseLayer更改为类的名称。

添加“lodash。Clonedeep ": "^4.5.0"到你的package.json。然后像这样使用:

import * as _ from 'lodash';

...

const copy = _.cloneDeep(original)

你也可以有这样的东西:

class Entity {
    id: number;

    constructor(id: number) {
        this.id = id;
    }

    clone(): this {
        return new (this.constructor as typeof Entity)(this.id) as this;
    }
}

class Customer extends Entity {
    name: string;

    constructor(id: number, name: string) {
        super(id);
        this.name = name;
    }

    clone(): this {
        return new (this.constructor as typeof Customer)(this.id, this.name) as this;
    }
}

只是要确保在所有Entity子类中覆盖clone方法，否则最终会得到部分克隆。

它的返回类型将始终与实例的类型匹配。

我的看法是:

Object.assign(…)只复制属性，我们丢失了原型和方法。

Object.create(…)不是为我复制属性，只是创建一个原型。

对我有用的是使用Object.create(…)创建一个原型，并使用Object.assign(…)将属性复制到它:

因此对于对象foo，像这样进行克隆:

Object.assign(Object.create(foo), foo)