Question

我有一个要传递输入值PreferredContactMethods的组件。

我要初始化另一个变量AlternativeContactMethods并为preferredContactMethods分配相同的值。

我尝试过：

Object.assign

@Input()
preferredContactMethods: Array<string>;

alternateContactMethods: Array<string> = Object.assign(this, this.preferredContactMethods);

直接分配

@Input()
preferredContactMethods: Array<string>;

alternateContactMethods: Array<string> = this.preferredContactMethods;

没有用

任何建议或示例都会有所帮助。

Answer 1

Angular为您提供了interceptor for input property changes。这将为您提供仅在输入更改时设置值的机会。看起来像这样：

private _preferredContactMethods: Array<string>;
private _alternateContactMethods: Array<string>;

// Here you can set/compare/calculate/... when your input changes
@Input() set preferredContactMethods(args: Array<string>){
  this._preferredContactMethods = args;
  this._alternateContactMethods = args;
};

Answer 2

You need to do following to assign value:

import { Component, Input, OnInit } from '@angular/core';

export class YourComponent implements OnInit {

   @Input() preferredContactMethods: Array<string>;
   public alternateContactMethods: Array<string>

   ngOnInit(): void {
      console.log(this.preferredContactMethods);  // To check value is exist or not.
      this.alternateContactMethods = [...this.preferredContactMethods];. // Assign the copy of preferredContactMethods array
   }

}

Answer 3

 Patent component html file like this:
<Your-Component  [preferredContactMethods]="data" ></Your-Component>

Child Component.ts file   
import { Component, Input, OnInit } from '@angular/core';

export class YourComponent implements OnInit {

   @Input() preferredContactMethods: Array<string>;
   alternateContactMethods: Array<string>

   ngOnInit(): void {
      console.log(this.preferredContactMethods);  // To check value is exist or not.
      this.alternateContactMethods = this.preferredContactMethods;
   }

}

初始化并分配打字稿中的值

3 个答案: