Angular4 組件通訊方法大全

組件通訊，意在不同的指令和組件之間共享信息。如何在兩個多個組件之間共享信息呢。

最近在項目上，組件跟組件之間可能是父子關系，兄弟關系，爺孫關系都有。。。。。我也找找了很多關於組件之間通訊的方法，不同的方法應用在不同的場景，根據功能需求選擇組件之間最適合的通訊方式。下面我就總結一下關於組件通訊的N多種方法。

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>

結果:

 

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>

結果：

3.子獲得父實例

 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>

結果：

4.父獲得子實例

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>

結果：

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:記得在app.module.ts 加上providers: [KmyService]

import{Injectable } from '@angular/core';
@Injectable()
export class KmyService {
    i:number = 0;
}

結果：

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>

 

結果：

7.訂閱

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);
    }
}

結果：

 

以上七種組件與組件的通訊方式，可以選擇應用於適合的場景里面，根據情況吧。

 

此隨筆乃本人原創，如有疑問歡迎在下面評論，轉載請標明出處。

如果對您有幫助請動動鼠標右下方給我來個贊，您的支持是我最大的動力。