通过socket.id向客户端发送消息

Question

我只能在用户的套接字ID直接存储在io.sockets.on（’connect’）函数中时向用户发出消息。我不知道为什么在登录后尝试存储其套接字ID时为什么不起作用。

加工：

  var clients = {};
  /** A new socket connection has been accepted */
  io.sockets.on('connection', function (socket)
  {
    //Used to access session id
    var hs = socket.handshake;            
        clients[socket.id] = socket; // add the client data to the hash   
        users['brownj2'] = socket.id; // connected user with its socket.id

    socket.on('user-login', function(user){
      if(!users[username]){
        //users[username] = socket.id; // connected user with its socket.id
      }
    })

    socket.on('page-load', function(pid)
    {
      if(users['brownj2'])
      {        
        clients[users['brownj2']].emit('hello');
      }
      else
      {
        console.log("NOT FOUND BROWNJ2");
      }
    }
  }

无法运作：

  var clients = {};
  /** A new socket connection has been accepted */
  io.sockets.on('connection', function (socket)
  {
    //Used to access session id
    var hs = socket.handshake;            
        clients[socket.id] = socket; // add the client data to the hash

    socket.on('user-login', function(user){          
      if(!users['brownj2']){
        users['brownj2'] = socket.id; // connected user with its socket.id
      }
    })

    socket.on('page-load', function(pid)
    {
      if(users['brownj2'])
      {        
        clients[users['brownj2']].emit('hello');
      }
      else
      {
        console.log("NOT FOUND BROWNJ2");
      }
    }
  }

JavaScript客户端代码段

var socket = io.connect('');
socket.on("hello", function(){
  alert("Hi Jack");
  console.log("WEBSOCKET RECIEVED");
})

解决方案：感谢@alessioalex，
我不得不从登录页面中删除对socket.io的引用，并将以下内容添加到io.sockets.on（’connection’）中。

var hs = socket.handshake;

sessionStore.get(hs.sessionID, function(err, session){
  console.log("SESSION: " + util.inspect(session));

  clients[socket.id] = socket; // add the client data to the hash
  validUsers[session.username] = socket.id; // connected user with its socket.id
})

Answer 1

您的代码存在一些问题，首先是您不应该通过Socket.IO对用户进行身份验证，您应该确保用户只有在经过身份验证后才能进行连接。如果您使用的是Express，则以下文章可以为您提供很多帮助：http : //www.danielbaulig.de/socket-
ioexpress/

另外，您应该避免像这样发送消息，因为它在内部是Socket.IO的一部分，并且可能会更改：

io.sockets.socket(id).emit('hello');

相反（如果您想向特定客户端发送消息），最好保留一个对象，例如与连接的客户端（并在断开连接时删除客户端）：

// the clients hash stores the sockets
// the users hash stores the username of the connected user and its socket.id
io.sockets.on('connection', function (socket) {
  // get the handshake and the session object
  var hs = socket.handshake;
  users[hs.session.username] = socket.id; // connected user with its socket.id
  clients[socket.id] = socket; // add the client data to the hash
  ...
  socket.on('disconnect', function () {
    delete clients[socket.id]; // remove the client from the array
    delete users[hs.session.username]; // remove connected user & socket.id
  });
}

// we want at some point to send a message to user 'alex'
if (users['alex']) {
  // we get the socket.id for the user alex
  // and with that we can sent him a message using his socket (stored in clients)
  clients[users['alex']].emit("Hello Alex, how've you been");
}

当然，io.sockets.socket(id)虽然可以工作（实际上并未测试），但由于它是Socket.IO内部的一部分，因此可以随时对其进行更改，因此上面的解决方案更加“安全”。

您可能希望在客户端代码中更改的另一件事是var socket = io.connect('');with var socket = io.connect('http://localhost');，正如我们在Socket.IO的官方示例中看到的那样：http ://socket.io/#how-to-use