javascript - 通过 socket.id 向客户端发送消息

Question

当用户的套接字 id 直接存储在 io.sockets.on('connect') 函数中时，我似乎只能向用户发送消息。我不知道为什么在他们登录后尝试存储他们的套接字 id 时它不起作用。

工作:

  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   
        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");
      }
    }
  }

不工作:

  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 客户端代码片段

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')

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，您应该确保他们只有在经过身份验证后才能连接。如果您使用 Express，那么以下文章可以帮助您很多:http://www.danielbaulig.de/socket-ioexpress/

此外，您应该避免像这样发送消息，因为这是 Socket.IO 内部的一部分并且可能会发生变化:

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(并在断开连接后删除客户端):

// 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) 可能有效(实际上并未测试)，但它也可以随时更改，因为它是 Socket.IO 内部结构的一部分，所以我的解决方案以上更“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(''); 和 var socket = io.connect('http://localhost');，正如我们在Socket.IO的官方示例中看到的:http://socket.io/#how-to-use