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組件之間的共享可以有好幾種方式
父->子 input 方式
import {Component,Input} from 'angular2/core'; @Component({ selector: 'child', template: ` <h3>child {{content}}</h3> ` }) class Child { @Input() content:string; } @Component({ selector: 'App', directives: [Child], template: ` <h2>App</h2> <child [content]="i"></child> ` }) export class App { i:number = 0; constructor() { setInterval(()=> { this.i++; }, 1000) } }
子->父 output 方式
import {Output,EventEmitter,Component} from 'angular2/core'; @Component({ selector: 'child', template: ` <h3>child</h3> ` }) class Child { @Output() updateNumberI:EventEmitter<number> = new EventEmitter(); i:number = 0; constructor() { setInterval(()=> { this.updateNumberI.emit(++this.i); }, 1000) } } @Component({ selector: 'App', directives: [Child], template: ` <h2>App {{i}}</h2> <child (updateNumberI)="numberIChange($event)"></child> ` }) export class App { i:number = 0; numberIChange(i:number){ this.i = i; } }
子獲得父實例
如果不了解forwardRef用處的的可以看 #11
@Host 表示這個Injector必須是host element在這里可以理解為 parent
import {Host,Component,forwardRef} from 'angular2/core'; @Component({ selector: 'child', template: ` <h3>child</h3> ` }) class Child { constructor(@Host() @Inject(forwardRef(()=> App)) app:App) { setInterval(()=> { app.i++; }, 1000); } } @Component({ selector: 'App', directives: [Child], template: ` <h2>App {{i}}</h2> <child></child> ` }) export class App { i:number = 0; }
父獲得子實例
子元素指令在父constructor時是獲取不到的,所以必須在組件的ngAfterViewInit生命周期鉤子后才能獲取,如果對組件生命周期不了解的話,可以參考#56
import {ViewChild,Component} from 'angular2/core'; @Component({ selector: 'child', template: ` <h3>child {{i}}</h3> ` }) class Child { i:number = 0; } @Component({ selector: 'App', directives: [Child], template: ` <h2>App {{i}}</h2> <child></child> ` }) export class App { @ViewChild(Child) child:Child; ngAfterViewInit() { setInterval(()=> { this.child.i++; }, 1000) } }
service 方式
import {Component,Injectable} from 'angular2/core'; @Injectable(); class KittencupService { i:number = 0; } @Component({ selector: 'child', template: ` <h3>child {{service.i}}</h3> ` }) class Child { constructor(public service:KittencupService){ } } @Component({ selector: 'App', directives: [Child], providers: [KittencupService], template: ` <h2>App {{i}}</h2> <child></child> ` }) export class App { constructor(service:KittencupService) { setInterval(()=> { service.i++; }, 1000) } }
service EventEmitter方式
import {Component,Injectable,EventEmitter} from 'angular2/core'; @Injectable() class KittencupService { change: EventEmitter<number>; constructor(){ this.change = new EventEmitter(); } } @Component({ selector: 'child', template: ` <h3>child {{i}}</h3> ` }) class Child { public i:number = 0; constructor(public service:KittencupService){ service.change.subscribe((value:number)=>{ this.i = value; }) } } @Component({ selector: 'App', directives: [Child], providers: [KittencupService], template: ` <h2>App {{i}}</h2> <child></child> ` }) export class App { i:number = 0; constructor(service:KittencupService) { setInterval(()=> { service.change.emit(++this.i); }, 1000) } }
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持億速云。
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