Socket.io 从 Node 中的多个套接字接收数据

Question

我几天前才开始使用 Node 进行开发。我目前正在开发一个使用 Node 作为服务器端应用程序的在线游戏。此应用程序仅向客户端提供 .html 和 .js 文件并处理游戏逻辑。 我正在使用 Socket.io 与客户端交换数据。当一个新的客户端通过 Socket.io 连接到服务器时，程序会寻找一个空间（包含两个用户的套接字和处理逻辑的游戏对象的对象数组）并放置用户（注册插座）在里面。 我已经能够正确地向每个客户端发送精灵的位置，但是我在从每个套接字检索数据时遇到问题：如果我尝试将一些数据从客户端发送到服务器，则该数据仅流经其中一个两个套接字，无论是哪个客户端发送的。

初始化房间数组

for(var i = 0; i < roomsNumber; i++) {
  //player1 and player 2 are going to store the sockets
  rooms[i] = { player1 : null, player2 : null, game: null};
}

Socket.io 处理连接

var io = require('socket.io')(server);

io.on('connection', function(socket){
  console.log("We have a new client: " + socket.id);
  insertPlayer(socket);

  socket.on('disconnect', function() {
    console.log("Client has disconnected: " + socket.id);
    removePlayer(socket);
  });
});

将客户添加到房间

function insertPlayer(socket) { //Check for an empty spot in a room
  for(var i = 0; i < rooms.length; i++) {
    if(!rooms[i].player1) {
      rooms[i].player1 = socket; //Register the socket to the room
      checkRooms();
      return;
    }
    if(!rooms[i].player2) {
      rooms[i].player2 = socket; //Register the socket to the room
      checkRooms();
      return;
    }
  }
}

在房间满时创建 Game 对象（并在玩家离开时销毁它）

function checkRooms() { //Checks if a room is full to initialize the game
  for(var i = 0; i < rooms.length; i++) {
    if(rooms[i].player1 && rooms[i].player2 && !rooms[i].game) {
      rooms[i].game = new Game([rooms[i].player1, rooms[i].player2]); //The constructor passes the sockets
      console.log('New game started');
    }
    if((!rooms[i].player1 || !rooms[i].player2) && rooms[i].game) {
      rooms[i].game.endGame();
      rooms[i].game = null;
      console.log('Game stopped');
    }
  }
}

在 Game 类中接收数据

constructor(sockets) {
  this.sockets = sockets;
  this.snakes = [];
  var self = this;

  for(var i = 0; i < this.sockets.length; i++) {
    this.snakes[i] = new Snake(i*100 + 100, 200);
    var currentSnake = this.snakes[i];
    var currentSocket = this.sockets[i];

  currentSocket.on('keyPressed', function(data) {
    currentSnake.updateDirection(data); //Calls a Game method that updates the direction of the sprite 
    console.log(currentSocket.id + " - " + data);
  });
}

Answer 1

我发现Game 构造函数中的currentSnake 变量存在问题。该变量的作用域是您的整个构造函数，因此那里只有一个变量，但是您试图为每个玩家设置一个单独的变量，但这是行不通的。因此，每次收到keyPressed 消息时，无论密钥来自哪个玩家，您都在对同一条蛇进行操作。

如果您使用的是 node.js v6+，则将该构造函数中的 var currentSnake 更改为 let currentSnake，以便将变量单独限定为 for 循环的每次调用。

constructor(sockets) {
  this.sockets = sockets;
  this.snakes = [];
  var self = this;

  for(var i = 0; i < this.sockets.length; i++) {
    this.snakes[i] = new Snake(i*100 + 100, 200);
    // change these to be declared with let so they are separately scoped 
    //   for each invocation of the for loop
    let currentSnake = this.snakes[i];
    let currentSocket = this.sockets[i];

    currentSocket.on('keyPressed', function(data) {
      currentSnake.updateDirection(data); //Calls a Game method that updates the direction of the sprite 
      console.log(currentSocket.id + " - " + data);
    });
  }
}

或者，如果您运行的是旧版本的 node.js，请切换到 .forEach() 以替换 for 循环，因为这也会为循环的每次调用创建一个新的单独范围。

constructor(sockets) {
  this.sockets = sockets;
  this.snakes = [];
  var self = this;

  this.sockets.forEach(function(currentSocket, i) {
    this.snakes[i] = new Snake(i*100 + 100, 200);
    var currentSnake = this.snakes[i];

    currentSocket.on('keyPressed', function(data) {
      currentSnake.updateDirection(data); //Calls a Game method that updates the direction of the sprite 
      console.log(currentSocket.id + " - " + data);
    });
  });
}