用JavaScript实现一个代码简洁、逻辑不复杂的多级树

在网上找个很多的树实现，总感觉不尽如意，不是需要引用JS外部文件使用插件，就是代码过多让人看的眼花，实际上我只是想实现一个代码简洁、逻辑不复杂的树，费话不多说直接上代码：

1，首先写CSS样式，这个必需要写的头部最先渲染

<style> 
.ps{margin-left:10px;display:none;} .f { 
background: url("add.gif") no-repeat scroll -4px -21px; 
cursor: pointer; 
height: 35px; 
line-height: 37px; 
padding-left: 20px; 
} 
</style>

2，在页面主体中添加树的具体内容，此内容也可以动态展示（动态展示只要针对规则就很好实现了，这就不用说了吧偷笑）

<div class="f" id="sgc1">密码修改</div> 
<div class="f" id="sgc2">商品选择</div> 
<div class="f" id="sgc3" onclick="w('gc3')">分类设置</div> 
<div class="ps" id="gc3" style="display:none"> 
<div id="sfgc91" class="f" onclick="k('fgc91')">Must See</div> 
<div class="ps" id="fgc91"> 
<div class="f">设置MustSee商品</div> 
</div> 
<div id="sfgc93" class="f" onclick="k('fgc93')">Spotlight</div> 
<div class="ps" id="fgc93"> 
<div class="f">设置Spotlight商品</div> 
</div> 
<div id="sfgc94" class="f" onclick="k('fgc94')">Daily Specials</div> 
<div class="ps" id="fgc94"> 
<div class="f">设置DailySpecials商品</div> 
</div> 
<div id="sfgc95" class="f" onclick="k('fgc95')">HotCategory</div> 
<div class="ps" id="fgc95"> 
<div class="f">设置HotCategory分类</div> 
<div class="f">设置HotCategory商品</div> 
</div> 
<div id="sfgc96" class="f" onclick="k('fgc96')">Hot & Cool Picks</div> 
<div class="ps" id="fgc96"> 
<div class="f">设置Hot & Cool Picks商品</div> 
</div> 
<div id="sfgc97" class="f" onclick="k('fgc97')">FeaturedCategorie</div> 
<div class="ps" id="fgc97"> 
<div class="f">设置FeaturedCategorie分类</div> 
<div class="f">设置FeaturedCategorie商品</div> 
</div> 
<div id="sfgc98" class="f" onclick="k('fgc98')">You Might Also Like…</div> 
<div class="ps" id="fgc98"> 
<div class="f">设置You Might Also Like…分类</div> 
<div class="f">设置You Might Also Like…商品</div> 
</div> 
</div> 
<div class="f" id="sgc4" onclick="w('gc4')">系统设置</div> 
<div class="ps" id="gc4" style="display:none"> 
<div class="f">用户管理</div> 
</div>

3，重头戏来了，同鞋注意了，接下来实现JS的树形控制

function w(vd) { 
var ob = document.getElementById(vd); 
if (ob.style.display == "block" || ob.style.display == "") { 
ob.style.display = "none"; 
var ob2 = document.getElementById('s' + vd); 
ob2.style.background = "url(add.gif) -4px -21px no-repeat"; 
} 
else { 
ob.style.display = "block"; 
var ob2 = document.getElementById('s' + vd); 
ob2.style.background = "url(add.gif) -4px 4px no-repeat;"; 
} 
} 
function k(vd) { 
var ob = document.getElementById(vd); 
if (ob.style.display == "block") { 
ob.style.display = "none"; 
var ob2 = document.getElementById('s' + vd); 
ob2.style.background = "url(add.gif) -4px -21px no-repeat"; 
} 
else { 
ob.style.display = "block"; 
var ob2 = document.getElementById('s' + vd); 
ob2.style.background = "url(add.gif) -4px 4px no-repeat;"; 
} 
}

4，运行实例图如下：