function wetherScroll(){
    var startX = startY = endX =endY =0;
    var body=document.getElementsByTagName("body");
    body.bind('touchstart',function(event){
      var touch = event.targetTouches[0];
      //滑動起點的坐標
      startX = touch.pageX;
      startY = touch.pageY;
      // console.log("startX:"+startX+","+"startY:"+startY);
    });
    body.bind("touchmove",function(event){
      var touch = event.targetTouches[0];
      //手勢滑動時，手勢坐標不斷變化，取最后一點的坐標為最終的終點坐標
        endX = touch.pageX;
        endY = touch.pageY;
        // console.log("endX:"+endX+","+"endY:"+endY);
    })
    body.bind("touchend",function(event){
      var distanceX=endX-startX,
        distanceY=endY - startY;
        // console.log("distanceX:"+distanceX+","+"distanceY:"+distanceY);
        //移動端設備的屏幕寬度
        var clientHeight; =document.documentElement.clientHeight;
        // console.log(clientHeight;*0.2);
        //判斷是否滑動了，而不是屏幕上單擊了
        if(startY!=Math.abs(distanceY)){
 //在滑動的距離超過屏幕高度的20%時，做某種操作
          if(Math.abs(distanceY)>clientHeight*0.2){
 //向下滑實行函數(shù)someAction1，向上滑實行函數(shù)someAction2
          distanceY <0 ? someAction1():someAction2();
        }
        }
        startX = startY = endX =endY =0;
    })
}