详解Angular父子组件间如何传值?

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时间:2021-03-22
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Angular中父子组件传值

官方地址:https://angular.cn/guide/component-interaction#component-interaction

1. 父组件给子组件传值

  • 说明: 父组件给子组件传值的时候,父组件中在子组件的选择器上绑定数据即可<app-hero-child [transData]='tran_childData'></app-hero-child>
  • 子组件接收的时候需要引入input模块import { Component, OnInit, Input} from '@angular/core'
  • 子组件还需要使用语法糖的形式接收父组件传递的参数@input() transData

1.1 父组件hero-parent

1、hero-parent.component.html

<p>这是父组件</p>
<app-hero-child [transData]='tran_childData'></app-hero-child>

2、hero-parent.component.ts

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

@Component({
    selector: 'app-hero-parent',
    templateUrl: './app-hero-parent.component.html',
    styleUrls: ['./app-hero-parent.component.sCSS']
})
export class HeroesComponent implements OnInit {
    tran_childData:string = '这是父组件传递给子组件的数据'
    constructor() {}
    ngOnInit(): void {}
}
1.2 子组件hero-child

1、hero-child.component.html

<p>{{transData}}</p>

2、hero-child.component.ts

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

@Component({
    selector: 'app-hero-child',
    templateUrl: './app-hero-child.component.html',
    styleUrls: ['./app-hero-child.component.scss']
})
export class DetAIlComponent implements OnInit {
    @Input() transData: string
    constructor() {}
    ngOnInit(): void {
        console.log(this.transData)
    }
}
1.3 效果图

详解Angular父子组件间如何传值?

2. 子组件给父组件传递参数

  • 说明:子组件给父组件传递参数的时候需要导入OutputEventEmitter,引入模块import { Component, OnInit, Output, EventEmitter} from '@angular/core'
  • 使用的时候需要先暴露一个方法@Output() childEvent = new EventEmitter()用来使用emit传递数据
  • 具体使用this.childEvent.emit('我是子组件传递的数据')

2.1 子组件hero-child

  1. hero-child.component.html
    <button (click)='transData_to_parent()'>我是子组件,给父组件传递参数</button>
  2. hero-child.component.ts
    import { Component, OnInit, Output, EventEmitter} from '@angular/core'
    
    @Component({
        selector: 'app-hero-child',
        templateUrl: './app-hero-child.component.html',
        styleUrls: ['./app-hero-child.component.scss']
    })
    export class DetailComponent implements OnInit {
        @Output() childEvent = new EventEmitter()
        constructor() {}
        ngOnInit(): void {},
        // 给父组件传递参数
        transData_to_parent() {
            this.childEvent.emit('我是子组件传递的数据')
        }
    }

2.2 父组件hero-parent

1、hero-parent.component.html

<p>这是父组件</p>
<p>{{receiceData}}</p>
<app-hero-child (childEvent)='receive_child_data($event)'></app-hero-child>

2、hero-parent.component.ts

import { Component, OnInit } from '@angular/core'
	
@Component({
    selector: 'app-hero-parent',
    templateUrl: './app-hero-parent.component.html',
    styleUrls: ['./app-hero-parent.component.scss']
})
export class HeroesComponent implements OnInit {
    constructor() {}
    ngOnInit(): void {}
    receiceData:string
    // 接收子组件传递的数据
    receive_child_data(data) {
        this.receiceData = data
    }
}

2.3 效果图

详解Angular父子组件间如何传值?

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