vue前端socket显示已连接，NodeJs后台却没有反应，请大家帮忙看看哪出问题了？

Question

代码如下：

前端

import VueSocketIO from 'vue-socket.io';
import SocketIO from 'socket.io-client';

Vue.use(new VueSocketIO({
        debug: true,
        connection: SocketIO('http://localhost:3001', { transports: ['websocket'] }), //'http://localhost:3001'就是后端地址

    })
);

 

 

后端

socketio.js文件:

//socket端口
let socket={}

function io(server){
    const io = require('socket.io')(server,{transports: ['websocket']})
    
    io.on('connection', (socket) => {
        console.log('a user connected');

        socket.on('message',data=>{
            console.log(data);
            socket.emit('showRemainder','得到msg');
        })


        socket.broadcast.emit('ground',"自律给我自由")
        socket.emit('showRemainder','得到msg');
    });
    console.log('socket is build');
}

socket.io=io

module.exports=socket

app.js文件，程序主入口：

//服务端口
const server = app.listen(3001, function () {
    let host = server.address().address
    let port = server.address().port
    console.log("应用实例，访问地址为 http://%s:%s", host, port)
})
//websocket端口
const socket=require('./socketio')
socket.io(server)


//设置允许跨域
app.use(function (req, res, next) {
    //指定允许其他域名访问 *所有
    res.setHeader("Access-Control-Allow-Origin", "*");
    //允许客户端请求头中带有的
    res.setHeader("Access-Control-Allow-Headers", "Content-Type,Content-Length, Authorization, Accept,X-Requested-With");
    //允许请求的类型
    res.setHeader("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
    res.setHeader("X-Powered-By", ' 3.2.1')
    //让options请求快速返回
    if (req.method == "OPTIONS") res.send(200);
    else next();
});

其中

运行效果：

 

后台啥也没有反应，跪求大佬们帮我看一下吧，感激

 

Answer 1

let host = server.address().address，打印一下host是不是localhost