javascript - 我无法访问服务器端的 socket.io？

Question

我最近开始使用 socket.io，并且开始掌握它的窍门。但一夜之间有些东西坏了，我不明白为什么。 当我调用socket.id(在socket.on中)时，我得到了未定义。但在其他 socket.on 函数中它工作正常。

谁能解释一下为什么它突然停止工作了？下面是我的代码。

这是我的 App.js:

socket.on('selectedcard', function(data){
    // if(localStorage.getItem("legstapel" != null)){
    //   var legstapel = localStorage.getItem("legstapel");
    // }
    // else{
    //   var legstapel = [];
    // }
    var legstapel = GAME_LIST[1].legstapel;
    //console.log(PLAYER_LIST[socket.id].hand[data.card]);
    console.log("SOCKET: ", socket.id); //this returns undefined
    console.log("SOCKET: ", SOCKET_LIST[socket.id].id); //and therefor this line throws an undefined error
    var infonext = dealnodeal(GAME_LIST[1].topstapel, PLAYER_LIST[socket.id].hand[data.card]);
    if(infonext[2] == true){
      socket.emit('Boerchoice');
    }
    if(infonext[0] == true && infonext[1] == true){
      currentturn = nextplayer(currentturn);
    }
    else if (infonext[0] == true && infonext[1] == false) {
      goAgain();
    }
    else{
      socket.emit('wrong');
    }

    if(infonext[0] == true){
      legstapel.push(PLAYER_LIST[socket.id].hand[data.card]);         //this is where i need socket.id to work.
      console.log(legstapel)
      GAME_LIST[1].topstapel = PLAYER_LIST[socket.id].hand[data.card];
      GAME_LIST[1].legstapel = legstapel;
    };
    console.log("topstackchange     " + GAME_LIST[1].topstapel);
    //for(var i in SOCKET_LIST){
      var socket = SOCKET_LIST[i];
      socket.emit("topstackchange", {
        topstapel: GAME_LIST[1].topstapel
      });
    //};
  });

这是客户端:

  PickCard = function(Cname){
    var turn = localStorage.getItem('turn')
    console.log(turn);
    if(turn == '1'){
      console.log("card selected : " + Cname);
      socket.emit('selectedcard', {
        card: Cname
      });
    }
    else{
      console.log("Het is niet jouw beurt!");
    }
  };

编辑: 这是简化的代码:

io.on('connect', function(socket){
  var player = Player(socket.id);
  SOCKET_LIST[socket.id] = socket;
  PLAYER_LIST[socket.id] = player;


  socket.on('selectedcard', function(data){
    console.log(socket.id); //this is undefined
  });

});

Answer 1

所以我认为问题是您在使用 socket 模块连接后没有使用 socket 变量。

io.on('connect', function (socket) {
    //this socket refers to the local socket variable which has ID
    socket.on('someEvent', function () {
        //socket.id will be available here.
    })
})

引用:Socket.IO docs

编辑:由于 OP 在使用这段代码时遇到问题，我附上 POC 以供引用。

服务器.js

var app = require('express')();
var server = require('http').Server(app);
var io = require('socket.io')(server);

server.listen(8080);
io.on('connection', function (socket) {
    socket.on('selectedcard', function (data) {
        console.log(socket.id); // this is working
        console.log(data);
    });
});

client.js(使用 Node 进行快速原型(prototype)设计)

var io = require('socket.io-client');

var socket = io.connect('http://localhost:8080');
socket.emit('selectedcard', {hey:'yaya'});

结果:

$ node server.js
U9GFjoTEzOsv0hmoAAAA
{ hey: 'yaya' }