Angular组件交互包含以下几种:
一.子组件获取父组件的内容
1.通过输入型绑定将数据从父组件传到子组件
2.通过Setter截听父组件值的变化
3.通过ngOnChanges()来截听输入值性值的变化
二.父组件获取子组件的内容
1.父组件监听子组件的事件
2.父组件与子组件通过本地变量互动
3.父组件调用@viewChild()
4.父组件和子组件通过服务来通讯
本节主要介绍: 2.父组件与子组件通过本地变量互动
父组件使用方式: <app-child #timer></app-child>
用#timer代表子组件app-child, 父组件可以直接调用子组件的函数
代码如下:
子组件:
import { Component, OnDestroy } from ‘@angular/core‘;
@Component({
selector: ‘app-countdown-timer‘,
template: ‘<p>{{message}}</p>‘
})
export class CountdownTimerComponent implements OnDestroy {
intervalId = 0;
message = ‘‘;
seconds = 11;
ngOnDestroy() { this.clearTimer(); }
start() { this.countDown(); }
stop() {
this.clearTimer();
this.message = `Holding at T-${this.seconds} seconds`;
}
private clearTimer() { clearInterval(this.intervalId); }
private countDown() {
this.clearTimer();
this.intervalId = window.setInterval(() => {
this.seconds -= 1;
if (this.seconds === 0) {
this.message = ‘Blast off!‘;
} else {
if (this.seconds < 0) { this.seconds = 10; } // reset
this.message = `T-${this.seconds} seconds and counting`;
}
}, 1000);
}
}
父组件:
import { Component } from ‘@angular/core‘;
import { CountdownTimerComponent } from ‘./countdown-timer.component‘;
@Component({
selector: ‘app-countdown-parent-lv‘,
template: `
<h3>Countdown to Liftoff (via local variable)</h3>
<button (click)="timer.start()">Start</button> //调动子组件的函数
<button (click)="timer.stop()">Stop</button>
<div class="seconds">{{timer.seconds}}</div>
<app-countdown-timer #timer></app-countdown-timer> //用timer代表子组件
`,
styleUrls: [‘../assets/demo.css‘]
})
export class CountdownLocalVarParentComponent { }
Anngular组件交互-----5.父组件与子组件通过本地变量互动
原文：https://www.cnblogs.com/estherSH/p/14314489.html