详解利用eventemitter2实现Vue组件通信

npm install --save eventemitter2

var EventEmitter2 = require('eventemitter2').EventEmitter2;
// emiter中定义的是eventemitter2实例，config中定义的是事件名
const eventConfig = {}

eventConfig.emitter = new EventEmitter2()

eventConfig.config = {
 "CHECK_CHANGES": "checkChanges"
 // 更多的事件名，往这里添加
}
export default eventConfig

export default class {
  constructor(evtInst){
    this.evtInst = evtInst
    this.listeners = {} // {eventName: [callback1,callback2...]}
  }
  // 将事件名evtName的回调绑定为callback，同时将事件名和回调存到listeners，方便后面移除事件使用
  addListener(evtName, callback){
    this.evtInst.on(evtName, callback)
    if(!this.listeners[evtName]){
      this.listeners[evtName] = [callback]
    }else{
      this.listeners[evtName].push(callback)
    }
  }
  removeListeners(){
    Object.keys(this.listeners).forEach(evtName => {
      this.listeners[evtName].forEach((callback, index) => {
        this.evtInst.off(evtName,callback)
      })
    })
  }
}

import EventManager from "@/utils/event_manager.js"
import eventConfig from "@/utils/event_config.js"
...
// 初始化event_manager实例
this.evtManagerInst = new EventManager(eventConfig.emitter)
// 用实例的addListener方法绑定事件
this.evtManagerInst.addListener(eventConfig.config.CHECK_CHANGES, obj => {
  this.value = Object.is(NaN,parseInt(obj.value))
})
this.evtManagerInst.addListener(eventConfig.config.CHECK_CHANGES, obj => {
  console.log("第二个事件也触发了！",obj)
})

import eventConfig from "@/utils/event_config.js"
...
// 传给事件回调函数的参数
let obj = {value: val, type: "", msg: ""}
// 触发事件
console.log("准备触发啦！")
eventConfig.emitter.emit(eventConfig.config.CHECK_CHANGES, obj)
// 事件触发后的处理
this.$message({type: obj.type, message: obj.msg})

beforeDestroy(){
  this.evtManagerInst.removeListeners()
}

var EventEmitter2 = require('eventemitter2').EventEmitter2;

// 事件名，实例
const emitter = {}

// 创建实例，定义事件名
emitter.install = function(Vue){
 Vue.prototype.$emit_inst = new EventEmitter2()
 Vue.prototype.$emit_name = {
  "CHECK_TYPE_TWO": "checkTypeTwo",
  "ANOTHER_EVENT": "anotherEvt"
  // 继续往后添加实例名
 }
}
export default emitter

import emitter from "./emitter"
Vue.use(emitter)

this.$emit_inst.on(this.$emit_name.CHECK_TYPE_TWO, obj => {
  this.value1 = Object.is(NaN,parseInt(obj.value))
  obj.type = this.value1 "success" : "warning"
  obj.msg = this.value1 "字符" : "数字"
  console.log("CHECK_TYPE_TWO第一次触发")
})
this.$emit_inst.on(this.$emit_name.CHECK_TYPE_TWO, obj => {
  console.log("CHECK_TYPE_TWO第二次触发")
})

this.$emit_inst.emit(this.$emit_name.CHECK_TYPE_TWO, obj)

beforeDestroy(){
  this.$emit_inst.removeAllListeners(this.$emit_name.CHECK_TYPE_TWO)
}