Socket.io复制消息

Question

我正在尝试使用Socket.io实施聊天服务。在开发模式下运行服务器一小段时间后，每当我尝试发送消息时，它都会复制我的消息（尤其是当我按Enter键时）。如何防止遇到这个问题？

除以下错误外，没有其他错误：

  

MaxListenersExceededWarning：检测到可能的EventEmitter内存泄漏。添加了11个newMessage侦听器。使用generator.setMaxListeners（）增加限制

这是我的代码：

server.js

var io = require('socket.io')(8081);
router.get('/chat', (req, res) => {
    if (req.session.userId) {
        teamName = req.session.teamName;
        faculty = req.session.faculty;
        console.log(teamName, faculty)
        io.on('connection', (socket) => {
            // Save new Messages to DB and show on the page
            socket.on('newMessage', message => {
                io.emit('newMessage', message)
                teamName = req.session.teamName;
                faculty = req.session.faculty;
                if (teamName && faculty) {
                    if (message != "") {
                        var newChatMessage = {
                            teamName: teamName,
                            faculty: faculty,
                            message: message
                        }
                        Chat.create(newChatMessage, (err, newChat) => {
                            if (err) {
                                console.log('[Chat Error]: ', err)
                            } else {
                                console.log(newChat)
                            }
                        })
                    }
                }
            })
        });
        // Get chats from mongoDB
        Chat.find({faculty: faculty}, (err, chatHistory) => {
            if (err) {
                console.log(err)
            }
            else {
                io.emit('messageHistory', chatHistory);
                console.log(chatHistory)
                res.render('main/chat', {
                    messages: chatHistory,
                    faculty: faculty,
                    teamName: teamName
                })
            }
        })
    }
    else {
        res.redirect('/')
    }
});

字体结尾：

<script>
    $(function() {
        var socket = io('http://localhost:8081');
        $('#sendMessage').on('click', function() {
            var newMessage = $('#m').val()
            if (newMessage != ""){
                socket.emit('newMessage', $('#m').val());
                $('#m').val('');
                return false
            }
        })
        socket.on('newMessage', function(message) {
            $('#messages').append($('<li>').text(message));
            window.scrollTo(0, document.body.scrollHeight);
        })
    })
    </script>