当用户断开连接时如何停止服务器上的计时器？(Node.js/socket.io)

Question

服务器上有一个计时器，当它启动时，就开始倒计时，但是当用户离开页面时，计时器继续运行，并在用户不再在页面上时触发。如何在用户离开页面之前或已经离开时停止此计时器？

    //Timer function
    function startTimer() {
        console.log("Timer statrted!");
        var countdown = 15000;
        setTimeout(function () {
            console.log("Timer done!");
        }, 15000);
    }

    socket.on("get data", function() {
         io.to(room_name).emit("data");
         //call timer
         startTimer(); //"Timer started!", "user disconnected", (after 15s) "Timer done!"
     });



     socket.on("disconnect" ,function(){
         console.log("user disconnected");   
     });

我试图停下clearTimeout()来socket.on("disconnect")，socket.on("disconnecting") 但它们对已经离开页面的当前用户不起作用...它们只为其他用户触发...

Answer 1

您需要存储timerID并在中使用相同的clearTimeout

var socketTimer;
    function startTimer() {
            console.log("Timer statrted!");
            var countdown = 15000;
            socketTimer = setTimeout(function () {
                console.log("Timer done!");
            }, 15000);
        }

    function stopTimer (){
        clearTimeout(socketTimer);
    }
        socket.on("get data", function() {
             io.to(room_name).emit("data");
             //call timer
             startTimer(); //"Timer started!", "user disconnected", (after 15s) "Timer done!"
         });



         socket.on("disconnect" ,function(){
             console.log("user disconnected");   
             stopTimer();
         });