相关链接
jQuery Treeview 完整实例下载：http://static.runoob.com/download/jquery-treeview.zip。
jQuery Treeview Github 地址：https://github.com/jzaefferer/jquery-treeview。
jQuery Treeview 提供了一个无序灵活的可折叠的树形菜单。适用于一些菜单的导航，支持基于 cookie 的持久性菜单。
<ul id="browser" class="filetree treeview-famfamfam">
<li><span class="folder">Folder 1</span>
<ul>
<li><span class="folder">Item 1.1</span>
<ul>
<li><span class="file">Item 1.1.1</span></li>
</ul>
</li>
<li><span class="folder">Folder 2</span>
<ul>
<li><span class="folder">Subfolder 2.1</span>
<ul id="folder21">
<li><span class="file">File 2.1.1</span></li>
<li><span class="file">File 2.1.2</span></li>
</ul>
</li>
<li><span class="folder">Subfolder 2.2</span>
<ul>
<li><span class="file">File 2.2.1</span></li>
<li><span class="file">File 2.2.2</span></li>
</ul>
</li>
</ul>
</li>
<li class="closed"><span class="folder">Folder 3 (closed at start)</span>
<ul>
<li><span class="file">File 3.1</span></li>
</ul>
</li>
<li><span class="file">File 4</span></li>
</ul>
</li>
</ul>