$(function(){

var iosScroll,
        startY,
        endY,
        startTime,
        endTime,
        speed,
        distance,
        duration,
        interval,
        a=3,
        timer=null,
        //-1为下，1为上
        flag;
$('#container').on('touchstart',function(e){
   startTime=(new Date()).getTime();
   startY=e.originalEvent.changedTouches[0].clientY;
});
$('#container').on('touchend',function(e){
    var agent        = navigator.userAgent,
    _isAndroid = /(Android)/i.test(agent),
    _isiOS     = /(iPhone|iPad|iPod|iOS)/i.test(agent) && !_isAndroid;
    if(_isiOS){
        clearInterval(timer);
        var a=1000;
        var dir=-1;
        endTime=(new Date()).getTime();
        endY=e.originalEvent.changedTouches[0].clientY;
        Speed();
        interval=(endTime-startTime)/1000;
        // duration,匀减速运动的时间，distance,匀减速运动的距离,V,初始速度
        var v=Math.abs(speed);
        duration=Math.abs(v/a).toFixed(2);
        distance=v*duration/2;
        var top=$(this).scrollTop();
        var me=this,count=1;
        timer=setInterval(function(){
            var nowTime = (new Date()).getTime();
            var t = (nowTime-endTime)/1000;
            var nowV = v + t*a*dir;
            var moveY =nowV*10/1000;
            me.scrollTop+=moveY*flag;
            if(nowV<0){
                clearInterval(timer);
            }
      },10);
    }
});
function Speed(){
    speed=(startY-endY)/((startTime-endTime)/1000);
    speed=speed>0?Math.ceil(speed):Math.floor(speed);
    speed<0?flag=1:flag=-1;
}

})