移动端左右滑动代码

　　　　//左右滑动切换
        var nStartY;
        var nStartX;
        var nChangY;
        var nChangX;
        document.getElementsByTagName('body')[0].addEventListener('touchstart',function(e){
            nStartY = e.targetTouches[0].pageY;
            nStartX = e.targetTouches[0].pageX;
        });
        document.getElementsByTagName('body')[0].addEventListener('touchmove',function(e){
            e.preventDefault();
        });
        document.getElementsByTagName('body')[0].addEventListener('touchend',function(e){
            nChangY = e.changedTouches[0].pageY;
            nChangX = e.changedTouches[0].pageX;
            var distance = nChangX - nStartX;
            var distance1 = nChangY - nStartY;

            if(distance > 50){//左滑
                alert('左滑');
            }else if(distance < -50){
                
                alert('右滑');
            }
        });