组件通讯,意在不同的指令和组件之间共享信息。如何在两个多个组件之间共享信息呢。
最近在项目上,组件跟组件之间可能是父子关系,兄弟关系,爷孙关系都有。。。。。我也找找了很多关于组件之间通讯的方法,不同的方法应用在不同的场景,根据功能需求选择组件之间最适合的通讯方式。下面我就总结一下关于组件通讯的N多种方法。
1.父→子 input
parent.ts
import { Component } from '@angular/core';
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
 i: number = 0;
 constructor() {
  setInterval(() => {
   this.i++;
  }, 1000)
 }
}
parent.html
<ion-header> <ion-navbar> <ion-title>Parent</ion-title> </ion-navbar> </ion-header> <ion-content padding> <h2>Parent</h2> <page-child [content]="i"></page-child> </ion-content>
child.ts
import { Component,Input } from '@angular/core';
@Component({
 selector: 'page-child',
 templateUrl: 'child.html',
})
export class ChildPage {
@Input() content:string;
 constructor() {
 }
}
child.html
<ion-content padding>
child:{{content}}
</ion-content>
结果:
2.子→父 output
parent.ts
import { Component } from '@angular/core';
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
 i: number = 0;
 numberIChange(i:number){
   this.i = i;
 }
}
parent.html
<ion-header>
 <ion-navbar>
  <ion-title>Parent</ion-title>
 </ion-navbar>
</ion-header>
<ion-content padding>
 <h2>Parent:{{i}}</h2>
 <page-child (changeNumber)="numberIChange($event)"></page-child>
</ion-content>
child.ts
import { Component, EventEmitter, Output } from '@angular/core';
@Component({
 selector: 'page-child',
 templateUrl: 'child.html',
})
export class ChildPage {
 @Output() changeNumber: EventEmitter<number> = new EventEmitter();
 Number: number = 0;
 constructor() {
  setInterval(() => {
   this.changeNumber.emit(++this.Number);
  }, 1000)
 }
}
child.html
<ion-content padding> child </ion-content>
结果:
3.子获得父实例
parent.ts
import { Component } from '@angular/core';
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
 i:number = 0;
}
parent.html
<ion-header>
 <ion-navbar>
  <ion-title>Parent</ion-title>
 </ion-navbar>
</ion-header>
<ion-content padding>
 <h1>parent: {{i}}</h1>
 <page-child></page-child>
</ion-content>
child.ts
import { Component, Input, EventEmitter, Output,Host,Inject,forwardRef } from '@angular/core';
import{ParentPage} from '../parent/parent';
@Component({
 selector: 'page-child',
 templateUrl: 'child.html',
})
export class ChildPage {
  constructor( @Host() @Inject(forwardRef(() => ParentPage)) app: ParentPage) {
    setInterval(() => {
      app.i++;
    }, 1000);
  }
}
child.html
<ion-content padding> child </ion-content>
结果:
4.父获得子实例
parent.ts
import {ViewChild, Component } from '@angular/core';
import{ChildPage}from '../child/child';
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
 @ViewChild(ChildPage) child:ChildPage;
  ngAfterViewInit() {
    setInterval(()=> {
      this.child.i++;
    }, 1000)
  }
}
parent.html
<ion-header>
 <ion-navbar>
  <ion-title>Parent</ion-title>
 </ion-navbar>
</ion-header>
<ion-content padding>
 <h1>parent {{i}}</h1>
 <page-child></page-child>
</ion-content>
child.ts
import { Component, Input, EventEmitter, Output,Host,Inject,forwardRef } from '@angular/core';
@Component({
 selector: 'page-child',
 templateUrl: 'child.html',
})
export class ChildPage {
  i:number = 0;
}
child.html
<ion-content padding>
<h2>child {{i}}</h2>
</ion-content>
结果:
5.service
parent.ts
import { Component } from '@angular/core';
import{myService}from '../child/myService'
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
   i:number=0;
  constructor(service:myService) {
    setInterval(()=> {
      service.i++;
    }, 1000)
  }
}
parent.html
<ion-header>
 <ion-navbar>
  <ion-title>Parent</ion-title>
 </ion-navbar>
</ion-header>
<ion-content padding>
  <h1>parent {{i}}</h1>
  <page-child></page-child>
</ion-content>
child.ts
import { Component} from '@angular/core';
import{myService}from "../child/myService"
@Component({
 selector: 'page-child',
 templateUrl: 'child.html',
})
export class ChildPage {
  constructor(public service:myService){
  }
}
child.html
<ion-content padding>
<h2>child {{service.i}}</h2>
</ion-content>
myService.ts
ps:记得在app.module.ts 加上providers: [KmyService]
import{Injectable } from '@angular/core';
@Injectable()
export class KmyService {
  i:number = 0;
}
结果:
6.EventEmitter
myService.ts
import {Component,Injectable,EventEmitter} from '@angular/core';
@Injectable()
export class myService {
  change: EventEmitter<number>;
  constructor(){
    this.change = new EventEmitter();
  }
}
parent.ts
import { Component } from '@angular/core';
import{myService}from '../child/myService'
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
  i:number = 0;
  constructor(service:myService) {
    setInterval(()=> {
      service.change.emit(++this.i);
    }, 1000)
  }
}
parent.html
<ion-header>
 <ion-navbar>
  <ion-title>Parent</ion-title>
 </ion-navbar>
</ion-header>
<ion-content padding>
  <h1>parent {{i}}</h1>
  <page-child></page-child>
</ion-content>
child.ts
import { Component, EventEmitter} from '@angular/core';
import{myService}from "../child/myService"
@Component({
 selector: 'page-child',
 templateUrl: 'child.html',
})
export class ChildPage {
  i:number = 0;
  constructor(public service:myService){
    service.change.subscribe((value:number)=>{
      this.i = value;
    })
  }
  
}
child.html
<ion-content padding>
 <h2>child {{i}}</h2>
</ion-content>
结果:
7.订阅
parent.ts
import { Component } from '@angular/core';
import{myService}from '../child/myService'
@Component({
 selector: 'page-parent',
 templateUrl: 'parent.html',
})
export class ParentPage {
  i:number=0;
  constructor(public service:myService) {
    setInterval(()=> {
       this.service.StatusMission(this.i++);
    }, 1000)
  }
}
parent.html
<ion-header> <ion-navbar> <ion-title>Parent</ion-title> </ion-navbar> </ion-header> <ion-content padding> <h1>parent</h1> <page-child></page-child> </ion-content>
child.ts
import { Component, Injectable } from '@angular/core'
import { myService } from "../child/myService"
import { Subscription } from 'rxjs/Subscription';
@Component({
  selector: 'page-child',
  templateUrl: 'child.html',
})
export class ChildPage {
  i:number=0;
  subscription: Subscription;
  constructor(private Service: myService) {
    this.subscription = Service.Status$.subscribe(message => {
      this.i=message;
    });
  }
  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}
child.html
<ion-content padding>
 <h2>child {{i}}</h2> 
</ion-content>
myService.ts
import { Injectable } from '@angular/core';
import { Subject } from 'rxjs/Subject';
@Injectable()
export class myService {
  private Source=new Subject<any>();
  Status$=this.Source.asObservable();
  StatusMission(message: any) {
    this.Source.next(message);
  }
}
结果:
以上七种组件与组件的通讯方式,可以选择应用于适合的场景里面,根据情况吧。希望对大家的学习有所帮助,也希望大家多多支持。
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