let express = require('express');
let app = express();

let server= require('http').Server(app);
let io = require('socket.io')(server);

io.on('connect', (socket) => {
  setInterval(() => {
    socket.emit('hi','hello')
  },2000)
  socket.on('hello', (data) => {
    console.log('hello',data)
    socket.emit('hi','get it')
  })
  socket.on('disconnect', (data) => {
    console.log('断开', data)
  })
})

server.listen(8080);

import Vue from 'vue'
import App from './App.vue'
import VueSocketIO from 'vue-socket.io'

Vue.config.productionTip = false

Vue.use(new VueSocketIO({
 debug: true,
 connection: 'http://127.0.0.1:8080',
}))

new Vue({
 render: h => h(App),
}).$mount('#app')

<script>
export default {
 sockets: {
  connect() {
   console.log('链接成功');
  },
  disconnect() {
   console.log('断开链接')
  },
  reconnect() {
   console.log('重新链接')
  },
  hi(res) {
   console.log('VueSocketIO', res)
  }
 }
}
</script>

import io from 'socket.io-client'
export default {
 mounted() {
  io('http://127.0.0.1:8080').on('hi', (res) => {
   console.log('socket.io-client', res)
  })
 },
}

this.$socket.emit('hello','i am wk')

this.sockets.listener.subscribe('hi', (data) => {
   console.log('++++++++++',data)
  })