1、封装websocket

新建文件夹"socket.ts"，路径："@/utils/socket"

export default (onMessage: Function) => {
  let socketUrl = 'ws://171.29.8.218:8080/ems/ws/screen' //socket请求地址
  let socket: WebSocket
  let lockReconnect = false
  let timer: ReturnType<typeof setTimeout>
  const createSocket = () => {
    try {
      socket = new WebSocket(socketUrl)
      init()
    } catch (e) {
      console.log('catch' + e)
      reconnect()
    }
  }
  const reconnect = () => {
    if (lockReconnect) return
    lockReconnect = true
    clearTimeout(timer)
    timer = setTimeout(() => {
      createSocket()
    }, 4000)
  }

  const init = () => {
    socket.onopen = function (event) {
      console.log('WebSocket:已连接')
      //心跳检测重置
      heartCheck.reset().start()
    }

    //接收到消息的回调方法
    socket.onmessage = function (event) {
      console.log('WebSocket:收到一条消息', event.data)
      const isHeart = /pong/.test(event.data)
      if (onMessage && !isHeart) {
        //触发自定义onMessage
        onMessage.call(null, event)
      }
      heartCheck.reset().start()
    }

    //连接发生错误的回调方法
    socket.onerror = function (event) {
      console.log('WebSocket:发生错误')
      reconnect()
    }

    //连接关闭的回调方法
    socket.onclose = function (event) {
      console.log('WebSocket:已关闭')
      heartCheck.reset() //心跳检测
      reconnect()
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常
    window.onbeforeunload = function () {
      socket.close()
    }
  }

  var heartCheck = {
    timeout: 8000,
    timeoutObj: setTimeout(() => {}),
    serverTimeoutObj: setInterval(() => {}),
    reset: function () {
      clearTimeout(this.timeoutObj)
      clearTimeout(this.serverTimeoutObj)
      return this
    },
    start: function () {
      var self = this
      clearTimeout(this.timeoutObj)
      clearTimeout(this.serverTimeoutObj)
      this.timeoutObj = setTimeout(function () {
        //这里发送一个心跳，后端收到后，返回一个心跳消息，
        //onmessage拿到返回的心跳就说明连接正常
        socket.send(
          JSON.stringify({
            action: 'ping'
          })
        )
        self.serverTimeoutObj = setTimeout(function () {
          //如果超过一定时间还没重置，说明后端主动断开了(因此timeout设定时间要比后端返回socket间隔时间长，否则会判定后端主动断开)
          console.log('关闭服务')
          socket.close() //如果onclose会执行reconnect，我们执行 websocket.close()就行了.如果直接执行 reconnect 会触发onclose导致重连两次
        }, self.timeout)
      }, this.timeout)
    }
  }
  createSocket()
}

2、全局注册

在文件夹"main.ts"中

import Websocket from "./utils/socket"
const onMessageList: Array<Function> = []; // 声明一个全局变量来收集onMessage列表，因为在不同的页面可能会有不同的处理
app.provide("onMessageList", onMessageList); // 全局注入
const onMessage = (event: any) => {
	// 遍历onMessage集合并触发
    onMessageList.forEach(f => {
        f.call(null, event);
    })
}
Websocket(onMessage); // 启动websocket

3、页面使用

import { inject } from "vue";
const onMessageList = inject("onMessageList"); // 接收注入
const socketMessage = (res) => {
    const data = JSON.parse(res.data); // 获取数据
};
onMessageList.push(socketMessage); // 将自定义处理事件插入onMessge集合