JS实现仿Windows7风格的网页右键菜单效果代码

本文实例讲述了JS实现仿Windows7风格的网页右键菜单效果代码。分享给大家供大家参考。具体如下：

这是一款JS仿Windows7风格的网页右键菜单，可以多级展开的右键菜单，原生JS。可参考性强，学习JavaScript的朋友不可错过。本菜单用户体验极佳，兼容性良好，无jQuery。

运行效果截图如下：

在线演示地址如下：

http://demo.jb51.net/js/2015/js-win7-style-web-right-menu-codes/

具体代码如下：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>自定义多级右键菜单</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
html,body{height:100%;overflow:hidden;}
body,div,ul,li{margin:0;padding:0;}
body{font:12px/1.5 \5fae\8f6f\96c5\9ed1;}
ul{list-style-type:none;}
#rightMenu{position:absolute;top:-9999px;left:-9999px;}
#rightMenu ul{float:left;border:1px solid #979797;background:#f1f1f1 url(images/line.png) 24px 0 repeat-y;padding:2px;box-shadow:2px 2px 2px rgba(0,0,0,.6);}
#rightMenu ul li{float:left;clear:both;height:24px;cursor:pointer;line-height:24px;white-space:nowrap;padding:0 30px;}
#rightMenu ul li.sub{background-repeat:no-repeat;background-position:right 9px;background-image:url(images/arrow_win7.png);}
#rightMenu ul li.active{background-color:#f1f3f6;border-radius:3px;border:1px solid #aecff7;height:22px;line-height:22px;background-position:right -8px;padding:0 29px;}
#rightMenu ul ul{display:none;position:absolute;}
</style>
<script type="text/javascript">
var getOffset = {
 top: function (obj) {
  return obj.offsetTop + (obj.offsetParent ? arguments.callee(obj.offsetParent) : 0)
 },
 left: function (obj) {
  return obj.offsetLeft + (obj.offsetParent ? arguments.callee(obj.offsetParent) : 0)
 }
};
window.onload = function ()
{
 var oMenu = document.getElementById("rightMenu");
 var aUl = oMenu.getElementsByTagName("ul");
 var aLi = oMenu.getElementsByTagName("li");
 var showTimer = hideTimer = null;
 var i = 0;
 var maxWidth = maxHeight = 0;
 var aDoc = [document.documentElement.offsetWidth, document.documentElement.offsetHeight];
 oMenu.style.display = "none";
 for (i = 0; i < aLi.length; i++)
 {
  //为含有子菜单的li加上箭头
  aLi[i].getElementsByTagName("ul")[0] && (aLi[i].className = "sub");
  //鼠标移入
  aLi[i].onmouseover = function ()
  {
   var oThis = this;
   var oUl = oThis.getElementsByTagName("ul");
   //鼠标移入样式
   oThis.className += " active";
   //显示子菜单
   if (oUl[0])
   {
    clearTimeout(hideTimer);
    showTimer = setTimeout(function ()
    {
     for (i = 0; i < oThis.parentNode.children.length; i++)
     {
      oThis.parentNode.children[i].getElementsByTagName("ul")[0] &&
      (oThis.parentNode.children[i].getElementsByTagName("ul")[0].style.display = "none");
     }
     oUl[0].style.display = "block";
     oUl[0].style.top = oThis.offsetTop + "px";
     oUl[0].style.left = oThis.offsetWidth + "px";
     setWidth(oUl[0]);
     //最大显示范围
     maxWidth = aDoc[0] - oUl[0].offsetWidth;
     maxHeight = aDoc[1] - oUl[0].offsetHeight;
     //防止溢出
     maxWidth < getOffset.left(oUl[0]) && (oUl[0].style.left = -oUl[0].clientWidth + "px");
     maxHeight < getOffset.top(oUl[0]) && (oUl[0].style.top = -oUl[0].clientHeight + oThis.offsetTop + oThis.clientHeight + "px")
    },300);
   }
  };
  //鼠标移出
  aLi[i].onmouseout = function ()
  {
   var oThis = this;
   var oUl = oThis.getElementsByTagName("ul");
   //鼠标移出样式
   oThis.className = oThis.className.replace(/\s?active/,"");
   clearTimeout(showTimer);
   hideTimer = setTimeout(function ()
   {
    for (i = 0; i < oThis.parentNode.children.length; i++)
    {
     oThis.parentNode.children[i].getElementsByTagName("ul")[0] &&
     (oThis.parentNode.children[i].getElementsByTagName("ul")[0].style.display = "none");
    }
   },300);
  };
 }
 //自定义右键菜单
 document.oncontextmenu = function (event)
 {
  var event = event || window.event;
  oMenu.style.display = "block";
  oMenu.style.top = event.clientY + "px";
  oMenu.style.left = event.clientX + "px";
  setWidth(aUl[0]);
  //最大显示范围
  maxWidth = aDoc[0] - oMenu.offsetWidth;
  maxHeight = aDoc[1] - oMenu.offsetHeight;
  //防止菜单溢出
  oMenu.offsetTop > maxHeight && (oMenu.style.top = maxHeight + "px");
  oMenu.offsetLeft > maxWidth && (oMenu.style.left = maxWidth + "px");
  return false;
 };
 //点击隐藏菜单
 document.onclick = function ()
 {
  oMenu.style.display = "none"
 };
 //取li中最大的宽度, 并赋给同级所有li
 function setWidth(obj)
 {
  maxWidth = 0;
  for (i = 0; i < obj.children.length; i++)
  {
   var oLi = obj.children[i];
   var iWidth = oLi.clientWidth - parseInt(oLi.currentStyle ? oLi.currentStyle["paddingLeft"] : getComputedStyle(oLi,null)["paddingLeft"]) * 2
   if (iWidth > maxWidth) maxWidth = iWidth;
  }
  for (i = 0; i < obj.children.length; i++) obj.children[i].style.width = maxWidth + "px";
 }
};
</script>
</head>
<body>
<center>自定义右键菜单，请在页面点击右键查看效果。</center>
<div id="rightMenu">
 <ul>
 <li><strong>JavaScript 学习</strong></li>
 <li>
  第一课
  <ul>
  <li>响应用户操作</li>
  <li>事件驱动</li>
  <li>元素属性操作</li>
  </ul>
 </li>
 <li>
  第二课
  <ul>
  <li>改变网页背景颜色</li>
  <li>函数传参</li>
  <li>126邮箱全选效果</li>
  <li>循环及遍历操作</li>
  </ul>
 </li>
 <li>
  第三课
  <ul>
  <li>
   JavaScript组成
   <ul>
   <li>ECMAScript</li>
   <li>DOM</li>
   <li>BOM</li>
   <li>JavaScript兼容性来源</li>
   </ul>
  </li>
  <li>JavaScript出现的位置、优缺点</li>
  <li>变量、类型、变量作用域</li>
  <li>
   闭包
   <ul>
   <li>什么是闭包</li>
   <li>简单应用</li>
   <li>闭包缺点</li>
   </ul>
  </li>
  <li>运算符</li>
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  <li>
   定时器的使用
   <ul>
   <li>setInterval</li>
   <li>setTimeout</li>
   </ul>
  </li>
  </ul>
 </li>
 </ul>
</div>
</body>
</html>

希望本文所述对大家的JavaScript程序设计有所帮助。