4.2号作业讲解

点击出现更多的选项：

<style type="text/css">
       #ee{
		100px; 
		height:40px;
		border:1px solid #999;
		text-align:center;
		line-height:40px;
		vertical-align:middle;}
	.hh{
		100px; 
		height:40px;
		border:1px solid #999;
		text-align:center;
		line-height:40px;
		vertical-align:middle;
		background-color:#03C;}
</style>
</head>
<body>
  <div id="ee" onclick="Biao('nn1')">颜色</div>        因为是对下边的div进行操作
     <div id="nn1" style="display:none">                  所以nn1传到上边
        <div class="hh">蓝色</div>
        <div class="hh">白色</div>
        <div class="hh">红色</div>
        <div class="hh">绿色</div>
        <div class="hh">灰色</div>
     </div>
  <div id="ee" onclick="Biao('nn2')">个数</div>         同上
    <div id="nn2" style="display:none">
        <div class="hh">2ge</div>
        <div class="hh">3ge</div>
        <div class="hh">8ge</div>
        <div class="hh">4ge</div>
        <div class="hh">9ge</div>
   </div>
  <div id="ee">重量</div>
</body>
<script type="text/javascript">
function Biao(a)                                                      a形参接收一下上边
{
   var nn = document.getElementById(a);        先找到要操作的div，var变量接收
   if(nn.style.display=="none")                      判断：隐藏的话显示，显示的话隐藏
   {   
	  nn.style.display = "block";
   }
   else
   {
	   nn.style.display = "none";   
   }
}
</script>
</html>

初始形态　　点开颜色点开个数

鼠标放上出现选项：

<head>
<style type="text/css">
    #caidan   {
		100px; 
		height:40px;
		border:1px solid #999;
		text-align:center;
		line-height:40px;
		vertical-align:middle;}
    .yiji	      {
		100px; 
		height:40px;
		float:left;
		text-align:center;
		line-height:40px;
		vertical-align:middle;
		}
</style>
</head>
<body>
          <div id="caidan">
                    <div class="yiji" onmousemove="Shang('erji1')" onmouse="Hui(erji1)">首页
                           <div id="erji" style="display:none">     
                                       <div class="xiang"></div>
                                       <div class="xiang"></div>
                                       <div class="xiang"></div>
                           </div>
                   </div>
                    <div class="yiji" onmousemove="Shang('erji2')" onmouse="Hui()erji2">首页2
                             <div id="erji2" style="display:none">     
                                       <div class="xiang"></div>
                                       <div class="xiang"></div>
                                       <div class="xiang"></div>
                           </div>
                    </div>
                    <div class="yiji">首页3</div>
          </div>
</body>
<script type="text/javascript">
   function shang(a)
 {
             var erji=document.getElementById(a);
             erji.style.display = "block"                    
 }
  function Hui(a)
 {
             var erji=document.getElementById(a);      
             erji.style.display = "none"                    
 }
</script>
</html>

初始首页　首1

div做下拉列表：

<head>
 <style type="text/css">
	*{
		margin:0px auto;}
        #caidan
          {
              330px;
              height:40px;
              border:1px solid #999;
          }
       .xiang{
                320px;
                height:40px;
                border:1px solid #999;
                background-color:#0FF;
                text-align:center;
                line-height:40px;
                vertical-align:middle;
                display:none;
           }
     .xiang:hover{
                  color:#fff;
                  background-color:red;
               }
</style>
</head>    
<body>
        <div id="caidan" onclick="Xian()"></div>
         <div class="xiang" onclick="Xuan(this)">北京</div>
         <div class="xiang" onclick="Xuan(this)">上海</div>
         <div class="xiang" onclick="Xuan(this)">深圳</div>
         <div class="xiang" onclick="Xuan(this)">广州</div>
         <div class="xiang" onclick="Xuan(this)">济南</div>
</body>
    <script type="text/javascript">
            function Xian ()
     {
         var div= document.getElementByClassName("xiang");     对xiang操作
         for(var i=0;i<div.length;i++)                                              
          {
               div[i].style.display="block";  
           }
     }
         function Xuan(a)                                  触发一个点击事件
    {               
           var nr=a.innerHTML;                          找到xuan定义变量nr
             docunment.getElementById("caidan").innerHTML= nr       点击的时候caidan变nr
             var xiang = document.getElementsByClassName("xiang");点击完以后剩下的的要隐藏，隐藏的是xiang
            for(var i=0;i<xiang.lengh;i++)     所有都隐藏
            {
                 xiang[i].style.display ="none";
            }
    }
 </script>
</html>

　点击以后没有隐藏点击以后隐藏其他

选项卡：

<style type="text/css">
	*{
		margin:0px auto;}
	#ka{
			320px;
			height:40px;
		}
	.kaming{
			100px;
			height:40px;
			text-align:center;
			vertical-align:middle;
			line-height:40px;
			float:left}
        .xiang{
		  320px;
		  height:300px;
		}
        </style>
 </head>    
  <body>
 <div id="ka">
        <div class="kaming" style="background-color:red;" onclick="Xian('xinwen')">新闻</div>
        <div class="kaming" style="background-color:green;" onclick="Xian('junshi')">军事</div>
         <div class="kaming" style="background-color:blue;" onclick="Xian('yule')">娱乐</div>
  </div>
     <div id="xinwen" class="xiang" style="background-color:red;"></div>
          <div id="junshi" class="xiang" style="background-color:green; display:none"></div>
        <div id="yule" class="xiang" style="background-color:blue; display:none"></div>
 </body>
 <script type="text/javascript">
         function Xian(a)
	{
	var div = document.getElementById(a);
	//恢复原样
        var xiang = document.getElementsByClassName("xiang");
	for(var i=0;i<xiang.length;i++)
	{
		xiang[i].style.display = "none";	
	}
	//变
	  div.style.display = "block";	
			
	}
    </script>
</html>

4.2号 作业讲解

4.2号作业讲解