1 var a = 0; 2 $(window).on(‘touchstart‘ , function(e){ 3     a = e.touches[0].screenY; 4 }); 5 $(window).on(‘touchmove‘ , function(e){ 6     var disY = e.touches[0].screenY - a; 7         if(disY > 0){ 8           alert(‘向下‘)   9         }else{10            alert(‘向上‘)11         }12 }