套接字.IO断开功能不工作

我的套接字差不多完成了。IO实现示例。唯一缺少的是disconnect事件的功能。

我试着把它放在io连接函数里面，外面，一切都浮现在我的脑海里。遗憾的是，断开连接功能根本不会被触发。

/* GET /backend */
router.get('/', function(req, res, next) {
  if (req.session && req.session.user) { // Check if session exists
  var currentUser = req.session.user[0].name; // save username according to session
    if(!req.session.user[0].io){
      req.app.get('io').on('connection', function(socket){ // Gets executed when user connects to /backend/
        req.session.user[0].io = true; // Sets the io session to true
        console.log("IO SESSION SET : "+ req.session.user[0].io +" for user " + currentUser);
      });
    if(req.session.user[0].io){
      req.app.get('io').on('disconnect', function(){
        req.session.user[0].io = false;
        console.log("IO SESSION SET : "+ req.session.user[0].io +" for user " + currentUser);
        req.app.get('io').emit('wentOffline', currentUser); // emit wentOffline to client js
      });
    }
      req.app.get('io').emit('cameOnline', currentUser); // emit function cameOnline to client js
    }
    // res.render('backend', { title: 'Backend' });
    // console.log(req.session.user[0].name);
    /*
    -------------------------
    #########################
    IF EVERYTHING FAILS - THE CODE BELOW IS THE NORMAL RENDER WITHOUT SOCKET IO
    #########################
    -------------------------
    */
    // lookup the user in the DB by pulling their email from the session
    User.getUser({ name: req.session.user.name }, function (err, user) {
      if (!user) {
        console.log("No User found");
        // if the user isn't found in the DB, reset the session info and
        // redirect the user to the login page
        // console.log(user);
        req.session.reset();
        res.redirect('/login');
      } else {
        // expose the user to the template
        res.locals.user = user;
        // render the dashboard page

        function passOnlineUsers(callback){ // Looks for All users who are online
          User.getOnlineUsers({}, function(err, res, fields){
            // console.log(res);
            if (err) throw err;
            callback(err, res);
          });
        }
        passOnlineUsers(function(err, result){
          res.render('backend', { title: 'Backend', viewer: req.session.user[0], online: result });
          // res.render('backend', { title: 'Backend', viewer: "", online: result });
        });
      }
    });
  } else {
    res.redirect('/login');
  }
});

如果需要，这里也是加载的客户端文件与io代码:

<script>
    var socket = io();
    // socket.emit('cameOnline', "new User");
    socket.on('cameOnline', function(name){
      console.log(name + " connected.");
      var $li = $('<li/>');
      $li.addClass(name);
      if($('#onlineUsers .'+name).length == 0){
        console.log(name + " is about to be added");
        $li.text(" "+ name);
        $('#onlineUsers').append($li);
      }else{
        console.log("no new user");
      }
      // $('#onlineUsers').append($("<span>").text(" " + name)).addClass(name);
    });
    socket.on('wentOffline', function(name){
      console.log(name +" is about to go offline");
      var toDel = $('#onlineUsers li.'+name);
      toDel.remove();
    });
    </script>

除了断开连接功能外，其他功能都可以正常工作。当用户上线时，cameOnline函数被触发，并在后端将该用户添加到列表中。

尽管当用户断开连接时-什么也没发生

有什么想法吗?oO