socketio io.on不是一个函数

Question

我在网络上看到了很多解决方案，但是它们对我没有多大帮助。

我已经在nodejs框架中创建了一个有效的express.js身份验证系统。我只想添加一个chat函数来帮助我们获取有关它的信息。

路线是

const dashboard = require('./routes/dashboard').dash;

并且调用函数是

app.use('/dashboard', dashboard)

在此代码页上，./rotes/dashboard.js我正在这样导出它们

const express = require('express');
const router = express.Router();
var app = express();
const io = require('socket.io');
const fs = require('fs');

const { ensureAuthenticated } = require('../db/auth.js');


//exporting dashboard 
module.exports = {
  dash: router.get('/', (req,res)=>{
    var chat = io.on('connection', (socket)=>{
      console.log('chat is connected');
    })
    res.render('dashboard', {chat:chat});

  })
}

但我遇到此错误：

io.on is not a function
TypeError: io.on is not a function
    at E:\expressBasedLOginSignUP\routes\dashboard.js:13:19
    at Layer.handle [as handle_request] (E:\expressBasedLOginSignUP\node_modules\express\lib\router\layer.js:95:5)
    at next (E:\expressBasedLOginSignUP\node_modules\express\lib\router\route.js:137:13)
    at Route.dispatch (E:\expressBasedLOginSignUP\node_modules\express\lib\router\route.js:112:3)
    at Layer.handle [as handle_request] (E:\expressBasedLOginSignUP\node_modules\express\lib\router\layer.js:95:5)
    at E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:281:22
    at Function.process_params (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:335:12)
    at next (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:275:10)
    at Function.handle (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:174:3)
    at router (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:47:12)
    at Layer.handle [as handle_request] (E:\expressBasedLOginSignUP\node_modules\express\lib\router\layer.js:95:5)
    at trim_prefix (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:317:13)
    at E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:284:7
    at Function.process_params (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:335:12)
    at next (E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:275:10)
    at E:\expressBasedLOginSignUP\node_modules\express\lib\router\index.js:635:15

有人帮助我如何避免使用此功能，以及为什么会发生这种情况。

Answer 1

[socket.io返回一个函数，您必须调用该函数并将您的http服务器引用传递给它。

示例：

const app = require('express')();
const server = require('http').createServer(app);
const io = require('socket.io')(server);

然后您可以在其上调用事件。