为什么这个功能会多次触发？

Question

我遇到点击多次触发功能的问题。具体来说，在下面的代码中，userloggedin（）;单击时，函数会多次触发。通常情况下，它会在第一次触发，下次触发3次，下次触发6次。

var timer = null;
function sessCountdown() {
    var sec = 120;
    timer = setInterval(function() {
        sec--;
        if (sec >= 0) {
            span = document.getElementById("count");
            span.innerHTML = sec;
        }
    }, 1000);
}

function getUserInfo() {
    var getUserInfo = $.ajax({
        type: 'Get',
        url: Config.engineUrl + '?AUserSessionInfo',
        dataType: 'json',
        xhrFields: {
            withCredentials: true
        },
        crossDomain: true
    });
    getUserInfo.done(function(data, jqXHR) {
        var sessionModal = $('#session-modal');
        if (data.TimeLeft > 0 && data.TimeLeft <= 2 && !sessionModal.hasClass('in')) {
            sessionModal.modal('show');
            sessCountdown();
        } else if (data.TimeLeft === 0){
        $('.logout').trigger('click');
        }
        sessionModal.on('shown.bs.modal', function(e) {
            $('#btnSession').on('click', function() {
                clearInterval(timer);
                userLoggedin();
            });
        });
    });
}

//Check for session info every 60 seconds
setInterval(getUserInfo, 60000);

我感谢您提供解决此问题的任何提示。感谢。

更新的代码 - 使用分辨率

var timer = null;

function sessCountdown() {
    var sec = 120;
    timer = setInterval(function() {
        sec--;
        if (sec >= 0) {
            span = document.getElementById("count");
            span.innerHTML = sec;
        }
    }, 1000);
}

function getUserInfo() {
    var sessionModal = $('#session-modal'),
        getUserInfo = $.ajax({
            type: 'Get',
            url: Config.engineUrl + '?AUserSessionInfo',
            dataType: 'json',
            xhrFields: {
                withCredentials: true
            },
            crossDomain: true
        });
    getUserInfo.done(function(data, jqXHR) {
        if (data.TimeLeft > 0 && data.TimeLeft <= 2 && !sessionModal.hasClass('in')) {
            sessionModal.modal('show');
            sessCountdown();
        } else if (data.TimeLeft === 0) {
            $('.logout').trigger('click');
        }
    });
}

$('#btnSession').on('click', function() {
    clearInterval(timer);
    userLoggedin();
});

//Check for session info every 60 seconds
setInterval(getUserInfo, 60000);