实例

下拉列表,首先用div布局

 <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>无标题文档</title>
       
        <style type="text/css">
		*{ margin:0 auto; padding:0;}
		#shou{
			900px;
			height:45px;
			text-align:center;
			line-height:45px;
			vertical-align:middle;
			
			}
			.zuoyi{
			float:left;
			}
		.diyi
		{
			298px;
			height:45px;
			background-color:#FF0;
			color:#063;
			text-align:center;
			line-height:45px;
			vertical-align:middle;
			border:1px solid #F39;
			
			}
			.diyi1{
			298px;
			height:45px;
			background-color:#030;
			
		
			color:#FFF;
			text-align:center;
			line-height:45px;
			vertical-align:middle;
			
			}
			#dier2{
				
				position:absolute;
				opacity:0.5;
				
				}
			#dier3{
			    
				position:absolute;
				opacity:0.5;
				}
			#dier4{
				
				position:absolute;
				opacity:0.5;
				}
 </style>
    </head>
    
    <body>
    <div id="shou">
    		<div class="zuoyi">
        
            <div class="diyi" onclick="shou('dier2')">首页</div>
                <div id="dier2" >
                    <div class="diyi1"><span>首页1</span></div>
                    <div class="diyi1">首页2</div>
                    <div class="diyi1">首页3</div>
                </div>
         	</div>
         
          	<div class="zuoyi">
                <div class="diyi" onclick="shou('dier3')">市场</div>
                <div id="dier3">
                    <div class="diyi1">市场1</div>
                    <div class="diyi1">市场2</div>
                    <div class="diyi1">市场3</div>
                </div>
            </div>
            
            <div class="zuoyi">
                <div class="diyi" onclick="shou('dier4')">人物</div>
                <div id="dier4">
                    <div class="diyi1">人物1</div>
                    <div class="diyi1">人物2</div>
                    <div class="diyi1">人物3</div>
                </div>
            </div>
       
    </div>
 </body>
</html>

  显示效果:

然后再加上

<script type="text/javascript">
	function shou(a)
	{
	var a = document.getElementById(a);
		if(a.style.display == "block")
			{
				a.style.display = "none";	
			}
			else
			{
				a.style.display = "block";
			}
	}
 </script>

  显示出的效果,可以单击合起来。如合起首页:

原文地址:https://www.cnblogs.com/xiaohaihuaihuai/p/7735958.html