在vue2.x里面简单使用socketio问题

npm init -y

npm i express@4.18.1

npm i socket.io@4.5.1

const app = require('express')()
const server = require('http').Server(app)
const io = require('socket.io')(server, { cors: true })
app.all('*', function (req, res, next) {
  res.header('Access-Control-Allow-Origin', '*')
  res.header('Access-Control-Allow-Headers', 'Origin,X-Requested-With,Accept,Content-type')
  res.header('Access-Control-Allow-Credentials', true)
  res.header('Access-Control-Allow-Methods', 'PUT,POST,GET,DELETE,OPTIONS')
  res.header('Content-Type', 'application/json;charset=utf-8')
  if (req.method.toLowerCase() == 'options') res.sendStatus(200)
  else next()
})
server.listen(3030, () => {
  console.log('listening on http://localhost:3030')
})

io.on('connect', (socket) => {
  console.log('有人连接成功了')
  socket.on('my other event', function (data) {
    console.log(data)
    socket.emit('news', data)
  })
  socket.emit('open', {data:'恭喜你收到了信息'})
  // 监听客户端断开
  socket.on('disconnect', () => {
    console.log('客户端断开')
  })
})

npm i socket.io-client@3.1.0 vue-socket.io@3.0.10

// socket.io
import VueSocketIO from 'vue-socket.io'
import SocketIO from 'socket.io-client'
Vue.use(
  new VueSocketIO({
    debug: false,
    connection: SocketIO('http://127.0.0.1:3030', {
      autoConnect: false // 取消自动连接     
    }),
    extraHeaders: { 'Access-Control-Allow-Origin': '*' }
  })
)

<template>
  <div class="wrap">
    <button @click="connected">连接Socket</button>
    <button @click="socketSendmsg">发送数据</button>
  </div>
</template>
<script>
export default {
  methods: {
    connected() {
      this.$socket.open() // 开始连接socket
    },
    socketSendmsg() {
      this.$socket.emit('my other event', { my: 'data' })
    }
  },
  sockets: {
    connecting() {
      console.log('正在连接')
    },
    disconnect() {
      console.log('Socket 断开')
    },
    connect_failed() {
      console.log('连接失败')
    },
    connect() {
      console.log('socket connected')
    },
    news(data) {
      console.log(data)
    },
    open(data) {
      console.log(data)
    }
  }
}
</script>

socket.on('my other event', function (data) {
    console.log(data)
    socket.emit('news', data)
  })