UnhandledPromiseRejectionWarning: TypeError: io.emit is not a function

Posted 2023-04-18

【中文标题】UnhandledPromiseRejectionWarning: TypeError: io.emit is not a function

【英文标题】：

【发布时间】：2021-01-21 00:29:03

【问题描述】：

我正在使用 Socket.io 进行实时图像上传过程，但我收到了下面提到的这个错误。我通过引用 answer 在不同的文件中编写套接字和 app.js 逻辑现在我想在控制器文件中发出该套接字事件但得到了错误

下面是我的代码

app.js

 // modules =================================================
 var express = require('express');
 var app = express();
 const logger = require('morgan');
 var bodyParser = require('body-parser');
 const indexRouter = require("./routes/index");
 const cors = require('cors');
 const path = require("path");
 const config = require("./environments/index");
 var http = require('http').Server(app);
 var sockets = require('./apis/socket.io');
 // configuration ===========================================
 var port = config.PORT || 8081; // set our port

 sockets.getSocketIo(http);

 app.use(bodyParser.json( limit: '50mb' ));

 app.use(bodyParser.urlencoded(
    limit: '50mb',
    extended: true,
    parameterLimit: 50000
 ));
 app.use(cors());
 app.use(logger('dev'))
 app.use("/api", indexRouter);

 app.use(express.static(path.join(__dirname, "/build")));

 app.get('/', function (req, res) 
    res.sendFile(__dirname + '/index.html');
 );

  http.listen(port, () => 
      console.log('Magic happens on port ' + port); // shoutout to the user
  );

 exports = module.exports = app;

这是socket.io.js文件代码

 var socketio = require('socket.io');
 var io = ;

 module.exports = 

getSocketIo: function (app) 

    let userId = 1

    io = socketio.listen(app);
    io.sockets.on('connection', function (socket) 
        console.log("new connection: " + socket.id);

        console.log(socket)


        console.log('socket connected')

        // let rooms = socket.id


        io.sockets.adapter.rooms
        if (io.nsps['/'].adapter.rooms["room-" + userId] && io.nsps['/'].adapter.rooms["room-" + 
  userId].length > 0) userId++;
        socket.join("room-" + userId);

        //Send this event to everyone in the room.
        io.sockets.in("room-" + userId).emit('connectToRoom', "You are in room no. " + userId);
        io.sockets.in(userId).emit('Image_upload', "Image uploading is started");
        console.log(socket.room)
        console.log(socket)
    );

;

这是api控制器的控制器代码

 report_data: async (req, res) => 
    if (!req.body.id) 
        logger.warn(error.MANDATORY_FIELDS);
        return res.status(500).send(error.MANDATORY_FIELDS)
    
    io.emit('progress', "Image is Uploading started Please Wait A minute");
    io.emit('error', "clients connected!");

    let Id = req.body.id;
    let path = `tmp/daily_gasoline_report/$Id`;

    req.body.data_url = path
    sequelize.sequelize.transaction(async (t1) => 
        let result = error.OK
        result.data = data

        logger.info(result);
        return res.status(200).send(result)
    ).catch(function (err) 
        logger.warn(err);
        console.log(err)
        return res.status(500).send(error.SERVER_ERROR)
    )
,

【参考方案1】：

您可以在文件中进行如下更改

app.js

// modules =================================================
var express = require('express');
var app = express();
const logger = require('morgan');
var bodyParser = require('body-parser');
const cors = require('cors');
const path = require("path");
const config = require("./environments/index");
var http = require('http').Server(app);
var io = require('socket.io').listen(http);
const indexRouter = require("./routes/index");

// configuration ===========================================
var port = config.PORT || 8081; // set our port

app.use(bodyParser.json( limit: '50mb' ));

app.use(bodyParser.urlencoded(
    limit: '50mb',
    extended: true,
    parameterLimit: 50000
));
app.use(cors());
app.use(logger('dev'))
app.use("/api", indexRouter);

app.use(express.static(path.join(__dirname, "/build")));

app.get('/', function (req, res) 
    res.sendFile(__dirname + '/index.html');
);

http.listen(port, () => 
    console.log('Magic happens on port ' + port); // shoutout to the user
);

app.locals.io = io

exports = module.exports = app;

socket.io.js

let io;

const getSocketIo = (http) => 
    let userId = 1

    io = require('socket.io')(http);
    io.sockets.on('connection', function (socket) 

        io.sockets.adapter.rooms
        if (io.nsps['/'].adapter.rooms["room-" + userId] && io.nsps['/'].adapter.rooms["room-" + userId].length > 0) userId++;
        socket.join("room-" + userId);

        //Send this event to everyone in the room.
        io.sockets.in("room-" + userId).emit('connectToRoom', "You are in room no. " + userId);
        console.log("new connection: " + socket.id);
        console.log('socket connected')
    );


module.exports = 
    getSocketIo,
    io
;

在你的控制器中，在你提到的 api 中添加这段代码，每当你想使用套接字时，在使用它之前添加这段代码

const io = req.app.locals.io;