DDR爱好者之家 Design By 杰米

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:

Angular4 组件通讯方法大全(推荐)

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:

Angular4 组件通讯方法大全(推荐)

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:

Angular4 组件通讯方法大全(推荐)

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:

Angular4 组件通讯方法大全(推荐)

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:

Angular4 组件通讯方法大全(推荐)

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:

Angular4 组件通讯方法大全(推荐)

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:

Angular4 组件通讯方法大全(推荐)

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。

DDR爱好者之家 Design By 杰米
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
DDR爱好者之家 Design By 杰米

稳了!魔兽国服回归的3条重磅消息!官宣时间再确认!

昨天有一位朋友在大神群里分享,自己亚服账号被封号之后居然弹出了国服的封号信息对话框。

这里面让他访问的是一个国服的战网网址,com.cn和后面的zh都非常明白地表明这就是国服战网。

而他在复制这个网址并且进行登录之后,确实是网易的网址,也就是我们熟悉的停服之后国服发布的暴雪游戏产品运营到期开放退款的说明。这是一件比较奇怪的事情,因为以前都没有出现这样的情况,现在突然提示跳转到国服战网的网址,是不是说明了简体中文客户端已经开始进行更新了呢?