NodeJS，Express，Sockets.io：无法获取.on（“连接”...在服务器上触发

我正在尝试将sockets.io集成到我的快递应用程序中 . 我使用快速生成器来格式化我的应用程序，所以我必须在bin / www中设置我的websocket . 我找到了一个类似的问题，并应用了找到的答案here，指示我在app.js中创建我的套接字对象，将其附加到app对象，并通过bin / www中的导出访问它以将其附加到服务器 .

这是我的app.js文件：

var express = require('express'),
    path = require('path'),
    favicon = require('serve-favicon'),
    bodyParser = require('body-parser'),
    sanitizer = require('sanitizer'),
    socket_io = require('socket.io'),

    config = require('./lib/config'),

    db = require('./lib/db'),
    fs = require('fs'),

    app = express(),
    io = socket_io();

app.io = io;

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(bodyParser.json({strict: false}));
app.use(bodyParser.urlencoded({ extended: false }));
app.use(express.static(path.join(__dirname, 'public')));

app.use(function(req,res,next){
    req.io = io;
    next();
});

app.io.sockets.on('connection', function(socket){
    console.log('connected!');
});

app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.json({
        code: err.status,
        err: err.message
    }).end();
});

module.exports = app;

这是我的bin / www文件，关于socket.io和http服务器：

var app = require('../app');
var debug = require('debug')('fresco:server');
var http = require('http');

/**
 * Get port from environment and store in Express.
 */

var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);

/**
 * Create HTTP server.
 */

var server = http.createServer(app);

/**
 * Socket.io
 */

app.io.attach(server);

/**
 * Listen on provided port, on all network interfaces.
 */

server.listen(port);

我正试图通过 ws://localhost:3000/ 访问本地运行的服务器，但我在客户端没有得到任何响应 . 我是否在我的websockets服务器中快速实现了websocket中的websockets？我可以't imagine why this isn' t工作，因为在app.js中创建的对象正在成功传递到bin / www . 在bin / www的末尾放置console.log会显示以下内容：

{ nsps:
{ '/':
  { name: '/',
    server: [Circular],
    sockets: [],
    connected: {},
    fns: [],
    ids: 0,
    acks: {},
    adapter: [Object],
    _events: [Object] } },
_path: '/socket.io',
_serveClient: true,
_adapter: [Function: Adapter],
_origins: '*:*',
sockets:
{ name: '/',
 server: [Circular],
 sockets: [],
 connected: {},
 fns: [],
 ids: 0,
 acks: {},
 adapter: { nsp: [Circular], rooms: {}, sids: {}, encoder: {} },
 _events: { connection: [Function] } },
eio:
{ clients: {},
 clientsCount: 0,
 pingTimeout: 60000,
 pingInterval: 25000,
 upgradeTimeout: 10000,
 maxHttpBufferSize: 100000000,
 transports: [ 'polling', 'websocket' ],
 allowUpgrades: true,
 allowRequest: [Function],
 cookie: 'io',
 ws:
  { domain: null,
    _events: {},
    _maxListeners: undefined,
    options: [Object],
    path: null,
    clients: [] },
 _events: { connection: [Function] } },
 httpServer:
 { domain: null,
 _events:
  { connection: [Function: connectionListener],
    clientError: [Function],
    close: [Function],
    upgrade: [Function],
    request: [Function],
    error: [Function: onError],
    listening: [Function: onListening] },
 _maxListeners: undefined,
 _connections: 0,
 _handle:
  { fd: undefined,
    reading: false,
    owner: [Circular],
    onread: null,
    onconnection: [Function: onconnection],
    writeQueueSize: 0 },
 _usingSlaves: false,
 _slaves: [],
 allowHalfOpen: true,
 pauseOnConnect: false,
 httpAllowHalfOpen: false,
 timeout: 120000,
 _connectionKey: '4:null:3000' },
 engine:
 { clients: {},
 clientsCount: 0,
 pingTimeout: 60000,
 pingInterval: 25000,
 upgradeTimeout: 10000,
 maxHttpBufferSize: 100000000,
 transports: [ 'polling', 'websocket' ],
 allowUpgrades: true,
 allowRequest: [Function],
 cookie: 'io',
 ws:
  { domain: null,
    _events: {},
    _maxListeners: undefined,
    options: [Object],
    path: null,
    clients: [] },
 _events: { connection: [Function] } } }