定时器遇到的坑

// 商品倒计时用一个定时器来写
//type 是不同页面
var timecountdown = {
    Secondms_jx: 60 * 1000,
    minutems_jx: 1000,
    h: 100,
    timehms: false
};

timecountdown.updateEndTime = function(type) {
    var _that = this;
    $(".item-djx").each(function(i, el) {
        if(!this.num){
           var endTime = parseInt(this.getAttribute("endTime"));
       }else{
           var endTime=this.num;
       }       
        var key = parseInt(this.getAttribute("itemid"));


        if (endTime < 0) {
            return true; //跳过此次循环
        } else {
            endTime = endTime - 1000;
        }
        this.num=endTime;
        _that.clock_jx(key, endTime, type);
    });

    setTimeout(function() {
        _that.updateEndTime(type);
        if(!_that.timehms){
            _that.hmstime();
        }
    }, 1000);
}

timecountdown.clock_jx = function(key, diff, skin) {
    var _that = this;

    if (diff <= 0) {
        $("#leftTimeJx" + key).parent().hide();
        $("#leftTimeJx" + key).parent().parent().find('.jx-ing').show();
        $.post('/yunbuy/lottery', 'skin=' + skin + '&id=' + key, function(data) {
            setTimeout(function() {
                $('#itemDjx' + key).remove();
                $('#win-list .item-db').eq(0).before(data.html);
            }, 5000);
        }, 'json');
    } else {
        var DifferSecond = Math.floor(diff / _that.Secondms_jx);
        diff -= DifferSecond * _that.Secondms_jx;
        var DifferMinute = Math.floor(diff / _that.minutems_jx);
        diff -= DifferMinute * _that.minutems_jx;

        if (DifferSecond.toString().length < 2) DifferSecond = '0' + DifferSecond;
        if (DifferMinute.toString().length < 2) DifferMinute = '0' + DifferMinute;

        var sTime = "";
        sTime += "<span>" + DifferSecond + "</span><b>:</b>";
        sTime += "<span>" + DifferMinute + "</span><b>:</b>";
        sTime += "<span class='timeHm'>" + 99 + "</span>";
        document.getElementById("leftTimeJx" + key).innerHTML = sTime; //显示倒计时信息
    }
}
timecountdown.hmstime = function() {
    //毫秒单独计时
    var _that = this;

    clearInterval(_that.timehms);
    _that.timehms = setInterval(function() {

        if (_that.h <= 0) _that.h = 100;
        _that.h = parseInt(_that.h) - 1;
        if (_that.h.toString().length < 1) _that.h = '00';
        if (_that.h.toString().length == 1) _that.h = '0' + _that.h;
        if (_that.h.toString().length > 2) _that.h = '99';
        setTimeout(function() {
           if ($('.timeHm').length == 0) {
            clearInterval(_that.timehms);
            _that.timehms=false; //此处一定要赋值，不然下次 再次开启 我用的这个值得判断 就会不准，虽然定时器清了，但是那个值一直存在，可以说是定时器id
           };
        }, 5000);

        $('.timeHm').html(_that.h)
    }, 15);
}

timecountdown.hmstime();

清空定时器之后 输出timehms  这个值一直存在 而且占用内存  

 

for(var i=0;i<10;i++){

    var a=setInterval("1",10);

    console.log(a);

}

这个定时器其实开了10个，但是只有最后一个有名字，能控制，其他都控制不了，而且清不掉，占用内存。

会看到 开多少个定时器，他的id 会越来愈大。占用内存，小心内存泄露。因此 商城 多个计算 最好用循环，一次定时器搞定

，一个方法里最好只开一个定时器，再开之前先清定时器。方式定时器过多，控制不过来

 

 

 

 

浏览器机制  定时器的假死状态

定时器有一个问题，就是当页面中开一个定时器，然后你没有关闭页面，继续浏览其他网页，过一会（几分钟）你在浏览这个定时器，这个定时器，在这期间是假死状态，就是不执行，你在返回来看到的估计就是定时器只进行了几秒。

解决方案：把后台传过来的时间段，转化为本地时间几点过期，然后一直判断是否到达本地时间即可，解决这个bug

// 商品倒计时用一个定时器来写
//type 是不同页面
var timecountdown = {
    hours_jx: 60 * 60 * 1000,
    Secondms_jx: 60 * 1000,
    minutems_jx: 1000,
    h: 100,
    timehms: false
};

timecountdown.updateEndTime = function(type) {
    var _that = this;
    $(".item-djx").each(function(i, el) {
        if(!this.num){
            var endTime = parseInt(this.getAttribute("endTime"))+new Date().getTime();
            this.num=endTime;
       }else{
           var endTime=this.num;
       }       
        var key = parseInt(this.getAttribute("itemid"));


        var duringtime=endTime-new Date().getTime();
        duringtime = duringtime - 1000;
        if (duringtime <= 0) {

            if(this.onoff){

                return true; //跳过此次循环
            }
            $("#leftTimeJx" + key).parent().hide();
            $("#leftTimeJx" + key).parent().parent().find('.jx-ing').show();
            $.post('/yunbuy/lottery', 'skin=' + type + '&id=' + key, function(data) {
                setTimeout(function() {
                    $('#itemDjx' + key).remove();
                    $('#win-list .item-db').eq(0).before(data.html);
                }, 5000);
            }, 'json');
            this.onoff=true;
        } else {
            _that.clock_jx(key,duringtime);
        }

    });

    setTimeout(function() {
        _that.updateEndTime(type);
    }, 1000);
}

timecountdown.clock_jx = function(key, diff, skin) {
    var _that = this;

        var Differhours = Math.floor(diff / _that.hours_jx);
        diff -= Differhours *  _that.hours_jx;
        var DifferSecond = Math.floor(diff / _that.Secondms_jx);
        diff -= DifferSecond * _that.Secondms_jx;
        var DifferMinute = Math.floor(diff / _that.minutems_jx);
        diff -= DifferMinute * _that.minutems_jx;

        if (Differhours.toString().length < 2) Differhours = '0' + Differhours;
        if (DifferSecond.toString().length < 2) DifferSecond = '0' + DifferSecond;
        if (DifferMinute.toString().length < 2) DifferMinute = '0' + DifferMinute;

        var sTime = "";
        if(Differhours!='00'){
            sTime += "<span>" + Differhours + "</span><b>:</b>";
        }
        sTime += "<span>" + DifferSecond + "</span><b>:</b>";
        sTime += "<span>" + DifferMinute + "</span><b>:</b>";
        sTime += "<span class='timeHm'>" + 99 + "</span>";
        document.getElementById("leftTimeJx" + key).innerHTML = sTime; //显示倒计时信息

}

timecountdown.updateEndTime();