如何检测滚动方向

Question

当有人向下滚动某个元素时，我想运行一个函数。像这样：

 $('div').scrollDown(function(){ alert('down') });

 $('div').scrollUp(function(){ alert('up') });

但是这些功能不存在。有解决这个问题的方法吗？他们似乎能够做到。不幸的是源代码被压缩，所以没有运气... 

Answer 1

我最终设法弄清楚了，所以如果有人在寻找答案：&nbsp;//Firefox&nbsp;$('#elem').bind('DOMMouseScroll', function(e){&nbsp; &nbsp; &nbsp;if(e.originalEvent.detail > 0) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//scroll down&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log('Down');&nbsp; &nbsp; &nbsp;}else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//scroll up&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log('Up');&nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; &nbsp;//prevent page fom scrolling&nbsp; &nbsp; &nbsp;return false;&nbsp;});&nbsp;//IE, Opera, Safari&nbsp;$('#elem').bind('mousewheel', function(e){&nbsp; &nbsp; &nbsp;if(e.originalEvent.wheelDelta < 0) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//scroll down&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log('Down');&nbsp; &nbsp; &nbsp;}else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//scroll up&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log('Up');&nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; &nbsp;//prevent page fom scrolling&nbsp; &nbsp; &nbsp;return false;&nbsp;});