让BOOTSTRAP默认SLIDER支持触屏设备

var isTouch=('ontouchstart' in window);
if(isTouch){
    $(".carousel").on('touchstart', function(e){
        var that=$(this);
        var touch = e.originalEvent.changedTouches[];
        var startX = touch.pageX;
        var startY = touch.pageY;
        $(document).on('touchmove',function(e){
            touch = e.originalEvent.touches[] ||e.originalEvent.changedTouches[];
            var endX=touch.pageX - startX;
            var endY=touch.pageY - startY;
            if(Math.abs(endY)<Math.abs(endX)){
                if(endX > ){
                    $(this).off('touchmove');
                    that.carousel('prev');
                }else if (endX < -){
                    $(this).off('touchmove');
                    that.carousel('next');
                }
                return false;
            }
        });
    });
    $(document).on('touchend',function(){
        $(this).off('touchmove');
    });
}