angular4父组件向子组件传值，子组件向父组件传值的方法

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父组件向子组件传值   @Input

文件目录

父组件：

father.template.html

<h1>父组件</h1>
<cmt-child [data]='data'></cmt-child>

father.component.ts

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

@Component({
    selector: 'cmt-father',
    templateUrl: './father.template.html'
})
export class FatherComponent implements OnInit {
    data: any = '我是传往子组件的值'
    ngOnInit() {
    }

    ngOnChanges() {
    }

}

子组件：（使用@Input修饰器去接收）

childcomponent.ts

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

@Component({
    selector: 'cmt-child',
    templateUrl: './child.template.html'
})
export class ChildComponent implements OnInit {
    @Input() data: any;//接收父组件的值
    ngOnInit() {
        console.log(this.data)
    }

    ngOnChanges() {
        console.log(this.data)
    }

}

这样就把值从父组件传到了子组件！

子组件向父组件传值（子组件通过方法借助修饰器@output传值给父组件）

子组件

childcomponent.ts

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

@Component({
    selector: 'cmt-child',
    templateUrl: './child.template.html'
})
export class ChildComponent implements OnInit {
    @Output('checked') checkedBack = new EventEmitter<any>();
    id:any ="我是传给父组件的值"
    ngOnInit() {
    }

    ngOnChanges() {
    }
    checkedCallback() {
        this.checkedBack.emit(this.id);
    }
}

child.template.html.html

<h1>子组件</h1>
<button (click)='checkedCallback()'>点击传值给父组件</button>

父组件

father.template.html

<h1>父组件</h1>
<cmt-child (checked)="checkedBack($event)"></cmt-child>

father.component.ts

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

@Component({
    selector: 'cmt-father',
    templateUrl: './father.template.html'
})
export class FatherComponent implements OnInit {
    ngOnInit() {
    }

    ngOnChanges() {
    }
    
    checkedBack(event) {
        console.log(event)
    }
}

这样子组件通过点击就把值传递给了父组件！