HTML onclick下拉菜单

我必须对下面的按钮进行编码，当它被点击时，它将显示一个下拉菜单

我将如何处理这个问题，因为我以前从未遇到过这个问题

只需谷歌“下拉按钮javascript”

我同意Jerome C

我能给你的唯一分类是，通常有很多网站的标题是“最好的NNN下拉菜单”，或者用任何东西代替下拉菜单

他们通常很有帮助

在这种情况下：

非常简单，但它为您提供了一个起点

<style type="text/css">
<!--
body,td,th {
 font-family: Verdana, Geneva, sans-serif;
 font-size: 100%;
 color: #666;
}
body {
 background-color: #fff;
 margin-left: 20px;
 margin-top: 20px;
 margin-right: 20px;
 margin-bottom: 20px;
} 

a, a:hover, a:active, a:focus {
 outline:0; 
 direction:ltr;
}

.wrapper {
 position:relative; height:25px;
}

.mainmenu {
 position:absolute; 
 z-index:100;
 font-family:Verdana, Geneva, sans-serif;
 font-weight:normal;
 font-size:90%;
 line-height:25px;
 left:50%; 
 margin-left:-303px; 
 width:606px;
} 

ul.menu {
 padding:0; 
 margin:0; 
 list-style:none; 
 width:100px; 
 overflow:hidden; 
 float:left; 
 margin-right:1px;
} 

ul.menu a {
 text-decoration:none; 
 color:#fff; 
 padding-left:5px;
}

ul.menu li.list {
float:left;
width:250px;
margin:-32767px -125px 0px 0px;
background:url(images/top1.png) no-repeat left bottom;
}

ul.menu li.list a.category {
position:relative;
z-index:50;
display:block;
float:left;
width:120px;
margin-top:32767px;
background:transparent;
}

ul.menu li.list a.category:hover,
ul.menu li.list a.category:focus,
ul.menu li.list a.category:active {
 margin-right:1px;
 background-image:url(images/tophover1.png);
 background-repeat:no-repeat;
 background-position:left top;
}

ul.submenu {
 float:left; 
 padding:25px 0px 0px 0px; 
 margin:0; 
 list-style:none; 
 background-image:url(images/tophover1.png);
 background-repeat:no-repeat;
 background-position:left top;
 margin:-25px 0px 0px 0px;
}

ul.submenu li a {
float:left;
width:120px;
background:#369;
clear:left;
}

ul.submenu li a.endlist {
 background:url(images/bottom1.png);
}

ul.submenu li a.endlist:hover,
ul.submenu li a.endlist:focus,
ul.submenu li a.endlist:active {
background:url(images/bottomhover1.png);
}

ul.submenu a:hover,
ul.submenu a:focus,
ul.submenu a:active {
background:#900;
margin-right:1px;
}
-->


</style>


<div class="wrapper">
<div class="mainmenu">
<ul class="menu">
<li class="list">
 <a class="category" href="#Home">Home</a>
</li>
</ul>
<ul class="menu">
<li class="list">
 <a class="category" href="#about">About Us&nbsp;&nbsp;&raquo;</a>
 <ul class="submenu">
  <li><a href="#about1">About link 1</a></li>
  <li><a href="#about2">About link 2</a></li>
  <li><a href="#about3">About link 3</a></li>
        <li><a href="#about4">About link 4</a></li>
  <li><a class="endlist" href="#about5">About link 5</a></li>
 </ul>
</li>
</ul>
<ul class="menu">
<li class="list">
 <a class="category" href="#articles">Articles&nbsp;&nbsp;&raquo;</a>
 <ul class="submenu">
  <li><a href="#articles1">Articles link 1</a></li>
  <li><a href="#articles2">Articles link 2</a></li>
  <li><a href="#articles3">Articles link 3</a></li>
  <li><a class="endlist" href="#articles4">Articles link 4</a></li>
 </ul>
</li>
</ul>
<ul class="menu">
<li class="list">
 <a class="category" href="#news">News&nbsp;&nbsp;&raquo;</a>
 <ul class="submenu">
  <li><a href="#news1">News link 1</a></li>
  <li><a href="#news2">News link 2</a></li>
  <li><a class="endlist" href="#news3">News link 3</a></li>
 </ul>
</li>
</ul>
<ul class="menu">
<li class="list">
 <a class="category" href="#donate">Donate</a>
</li>
</ul>
<ul class="menu">
<li class="list">
 <a class="category" href="#contact">Contact</a>
</li>
</ul>
<!-- end mainmenu --></div>
<!-- end wrapper --></div>

或

http://www.texaswebdevelopers.com/blog/template_permalink.asp?id=129

http://www.1stwebdesigner.com/css/38-jquery-and-css-drop-down-multi-level-menu-solutions/