首页手记 DOM事件探秘--第5章编程挑战题

DOM事件探秘--第5章编程挑战题

标签：

Html/CSS JavaScript

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>下拉菜单</title>
    <style type="text/css">
body,ul,li{ margin:0; padding:0; font-size:13px;}
ul,li{list-style:none;}
#divselect{width:186px; margin:80px auto; position:relative; z-index:10000;}
#divselect cite{width:150px; height:24px;line-height:24px; display:block; color:#807a62; cursor:pointer;font-style:normal;
padding-left:4px; padding-right:30px; border:1px solid #333333; 
background:url(xjt.png) no-repeat right center;}
#divselect ul{width:184px;border:1px solid #333333; background-color:#ffffff; position:absolute; z-index:20000; margin-top:-1px; display:none;}
#divselect ul li{height:24px; line-height:24px;}
#divselect ul li a{display:block; height:24px; color:#333333; text-decoration:none; padding-left:10px; padding-right:10px;}
    </style>
   <script type="text/javascript">
window.onload=function(){
    var box=document.getElementById('divselect'),
        title=box.getElementsByTagName('cite')[0],
        menu=box.getElementsByTagName('ul')[0],
        as=box.getElementsByTagName('a'),
        index=0;
        flag1=0;
        flag2=0;
        p=0;

    // 点击三角时
    title.onclick=function(event){
      // 执行脚本

      event=event||window.event;
      if(event.stopPropagation){
        event.stopPropagation();
      }else{
        event.cancelBubble=true;
      }
      menu.style.display="block";

    }  

   // 滑过滑过、离开、点击每个选项时
      // 执行脚本
      for(i=0;i<as.length;i++){
        as[i].onmouseover=function(){
        for(j=0;j<as.length;j++){
           if(as[j].style.backgroundColor=="rgb(221, 221, 221)"){
                as[j].style.background=null;
            }   
          }
          this.style.background="#DDD";
        }
        as[i].onclick=function(){
          menu.style.display="none";
          title.innerHTML=this.innerHTML;
        }
        as[i].onmouseout=function(){
          this.style.background=null;
        }
      }
   // 点击页面空白处时
       // 执行脚本
       document.onclick=function(){
          menu.style.display="none";
       }

       window.onkeyup=function(e){
        e=e||window.event;
        if (e.keyCode==13) {
          if(flag1==0&&menu.style.display=="none"){
          menu.style.display="block";
            flag1=1;
          }else{

          for(i=0;i<as.length;i++){

           if(as[i].style.backgroundColor=="rgb(221, 221, 221)"){

             title.innerHTML=as[i].innerHTML;
           }

          }
        menu.style.display="none";
          flag1=0;
          }
        }

         for(i=0;i<as.length;i++){

           if(as[i].style.backgroundColor=="rgb(221, 221, 221)"){
             index=i;
             p=1;
         }

           }

        if (e.keyCode==38) {
          if(index>0){
            as[index%(as.length)].style.background=null;
          as[(index-1)%(as.length)].style.background="#DDD";
          index--;
          }else{
            as[index].style.background=null;
            index=as.length;
            as[index-1].style.background="#DDD";
            index--;
          }

        }
        if (e.keyCode==40) {
          if (flag2==0&&p==0) {
            as[index].style.background="#DDD";
            flag2=1;
          }else{
          as[index%(as.length)].style.background=null;
          as[(index+1)%(as.length)].style.background="#DDD";
          index++;
        }

        }
       }

 }
   </script>
</head>
<body>
    <div id="divselect">
      <cite>请选择分类</cite>
      <ul>
         <li id="li"><a href="javascript:;" selectid="1">ASP开发</a></li>
         <li><a href="javascript:;" selectid="2">.NET开发</a></li>
         <li><a href="javascript:;" selectid="3">PHP开发</a></li>
         <li><a href="javascript:;" selectid="4">Javascript开发</a></li>
         <li><a href="javascript:;" selectid="5">Java特效</a></li>
      </ul>
    </div>
</body>
</html>

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