Ionic4--事件驱动

npm install --save eventemitter3

1、定义公共的服务配置 EventEmitter

import { Injectable} from '@angular/core'; 
import {EventEmitter} from 'eventemitter3'; 

@Injectable({
	providedIn: 'root' 
})
export class EventService { 
    public eventEmit: any; 
    constructor() {
		// 定义发射事件
		this.eventEmit = new EventEmitter(); 
	}
}

2、用户中心页面监听事件广播

import { EventService } from '../services/event.service';

this.eventService.eventEmit.on('login',(result)=>{ 
    console.log('执行');
})

3、登录页面返回的时候发送广播

import { EventService } from '../services/event.service'; 
ionViewDidLeave(){
	this.eventService.eventEmit.emit('login','登录页面退出了'); 
}