Socket.io：无法向特定房间

Question

我在Node.js中构建服务器套接字，这是我无法向特定房间发送数据的问题。我试图在房间里打印所有socket-client id，它仍然会在那个房间打印所有套接字ID。

function SocketManager(serverSocket, app) {
    let self = this;
    self.io = socket.listen(serverSocket);

    self.io.on('connection', function (client) {

        let user_id;

        client.on('join', function (userId) {
            user_id = userId;
            logger.info("SOCKET: User " + userId + " connected with id " + client.id);
            client.join(userId);
        });

        client.on('disconnect', function () {
            if (user_id)
                logger.info("SOCKET: User " + user_id + " disconnected with id " + client.id);
        });

        client.on('push_data', function (sensor_data) {
            let sensor_id = sensor_data.sensorId;
            app.models.sensor.findById(sensor_id).then(function (sensor) {
                let userId = sensor.createdBy;
                if (self.io.nsps["/"].adapter.rooms[userId]) {
                    Object.keys(self.io.nsps["/"].adapter.rooms[userId].sockets).forEach(function (socket) {
                        logger.info(socket);
                    });
                    self.io.in(userId).emit('pull_data', sensor_data);
                }
                // self.io.emit('pull_data', sensor_data);
            });
        });

    });
}

当我替换self.io.in(userId).emit('pull_data', sensor_data)时 使用self.io.emit('pull_data', sensor_data)，客户端可以正常接收数据。客户端使用Swift SocketIO。