鼠标滚轮编程_javascript技巧

以前没有注意到这个滚轮，看到这里有一篇说这个的：http://www.javascriptsearch.com/guides/Advanced/articles/JSMouseScrolling.html

我把它转过来了。如果是在实际应用中，有的时候还是蛮有用的。主要是得到滚轮是向上滚还是向下滚。

注释的代码

function handle(delta) {
 if (delta  …;
 else
 …;
}

/** 事件句柄
 */
function wheel(event){
 var delta = 0;
 if (!event) /* For IE. */
 event = window.event;
 if (event.wheelDelta) { /* IE或者Opera. */
 delta = event.wheelDelta/120;
 /** 在Opera9中，事件处理不同于IE
 */
 if (window.opera)
 delta = -delta;
 } else if (event.detail) { /** 兼容Mozilla. */
 /** In Mozilla, sign of delta is different than in IE.
 * Also, delta is multiple of 3.
 */
 delta = -event.detail/3;
 }
 /** 如果 增量不等于0则触发
 * 主要功能为测试滚轮向上滚或者是向下
 */
 if (delta)
 handle(delta);
}

/** 初始化 */
if (window.addEventListener)
 /** Mozilla的基于DOM的滚轮事件 **/
 window.addEventListener('DOMMouseScroll', wheel, false);
/** IE/Opera. */
window.onmousewheel = document.onmousewheel = wheel;

在上面的代码中,handler函数里的代码就是你要写的，它有一个参数-delta，事实上，它只是代码鼠标此刻是向上滚或者是向下滚。如下所示，

<?xml version="1.0" encoding="UTF-8"?> <title> mousewheel delta - http://www.never-online.net </title> <meta http-equiv="ImageToolbar" content="no"> <meta name="author" content="never-online, BlueDestiny"> <meta name="keywords" content="never modules, Mozilla CSS, C#, .net, Refercence, BlueDestiny, never-online"> <meta name="description" content="BlueDestiny, never-online"> <meta name="title" content=" - http://www.never-online.net"> <meta name="creator.name" content="never-online, BlueDestiny"> <style type="text/css" media="all" title="Default"> </style> <script type="text/javascript"> //<![CDATA[ function handle(delta) { var s = delta + ": "; if (delta < 0) s += "down"; else s += "up"; document.getElementById('delta').innerHTML = s; } function wheel(event){ var delta = 0; if (!event) event = window.event; if (event.wheelDelta) { delta = event.wheelDelta/120; if (window.opera) delta = -delta; } else if (event.detail) { delta = -event.detail/3; } if (delta) handle(delta); } /* Initialization code. */ if (window.addEventListener) window.addEventListener('DOMMouseScroll', wheel, false); window.onmousewheel = document.onmousewheel = wheel; //]]> </script> <div id="delta">Scroll mouse wheel to see delta here.</div>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]