之前参加过一些基于HTML/CSS/JavaScript的项目，当在页面中需要生成一颗目录树时，总是首先想着网上有没有现成的生成树的源代码，比如dtree、zthee,或者使用一些javascript框架类库（比如目前Dojo和ExtJs）自带的树模型或插件。
今天趁项目不是很紧，有时间可以自己考虑原创一颗树，完成这个小的尝试后想想不是很难，效果如下：
如果您觉得我做的目录树效果不怎么样，您可以去投靠上面我提到的现成的做法，可以不用继续阅读本文。
上面示例的原代码如下，为了保持完整性，我没有将代码中德HTML、CSS、JavaScript分开，都放在一个文件里，若你引用我提供的层级目录树代码，请将三者合理放在不同的文件中。需要注意的是，您需要在目录树上配置链接地址。相信你熟悉HTML、CSS、JavaScript，应该知道如何对下面的代码进行改造。享受你的美好生活吧，感受网页开发可以如此简单！
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="author" content="心梦缘ocean ocl" /> <title>My tree demo</title> <style type="text/css"> /*主页面样式*/ .leftNav { width: 20%; height:500px; border:#B9E0F7 1px solid; margin-left: 1%; margin-right: 1%; } #footer { color:#808080; line-height: 1.6em; padding: 0 0 1em 0; } /*我的树样式表*/ .treeDiv { color: #636363; font-size: 14px; font-weight: normal; background-color: #fff; color: black; overflow: auto; padding: 0 0 1em 0; overflow-x: hidden; } .treeNode { white-space: nowrap; text-indent: -14px; margin: 6px 2px 5px 14px; } a.treeUnselected:hover, a.treeSelected:hover { background-color: #BFD9ED; text-decoration: none; } a.treeUnselected, a.treeSelected { color: black; padding: 1px 3px 1px 0; text-decoration: none; } a.treeSelected { background-color: #B9E0F7; } a.treeUnselected { background-color: transparent; } .treeSubnodes { display: block; } .treeSubnodesHidden { display: none; } .treeNode img.treeNoLinkImage, .treeNode img.treeLinkImage { height: 15px; margin-left: 5px; margin-right: 0px; width: 15px; } .treeNode img.treeLinkImage { cursor: pointer; } div.treeNode a, div.treeNode span.apiRoot { display: inline-block; margin-left: 24px; text-indent: 0; white-space: normal; width: 95%; word-wrap: break-word; } div.treeNode span.category { cursor: pointer; } </style> </head> <body> <div class="leftNav"> <div id="samplesToc"> <div id="tree" style="top: 35px; left: 0px;" class="treeDiv"> <div id="treeRoot" onselectstart="return false" ondragstart="return false"> <div class="treeNode"> <img src="../graphics/treenodeplus.gif" onclick="expandCollapse(this.parentNode)" class="treeLinkImage"> <span onclick="expandCollapse(this.parentNode)" class="category">目录节点一 </span> <div class="treeSubnodesHidden"> <div class="treeNode"> <img src="../graphics/treenodeplus.gif" onclick="expandCollapse(this.parentNode)" class="treeLinkImage"> <span onclick="expandCollapse(this.parentNode)" class="category">目录节点一子目录 </span> <div class="treeSubnodesHidden"> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">二级叶子结点一</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">二级叶子结点二</a> </div> </div> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点一</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点二</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点三</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点四</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点五</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点六</a> </div> </div> </div> <!--end block--> <div class="treeNode"> <img src="../graphics/treenodeplus.gif" onclick="expandCollapse(this.parentNode)" class="treeLinkImage"> <span onclick="expandCollapse(this.parentNode)" class="category">目录节点二</span> <div class="treeSubnodesHidden"> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点一</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点二</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点三</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点四</a> </div> <div class="treeNode"> <a href="#" class="treeUnselected" onclick="clickAnchor(this)">叶子结点五</a> </div> </div> </div> <!--end block--> </div> </div> </div> <!-- end samplesToc --> </div> <!-- end leftNav --> <div class="right content"> </div><!-- end main content--> <div id="footer" align="center"> </div><!-- end footer--> <script type="text/javascript"> var treeSelected = null;//选中的树节点 var imgPlus = new Image(); imgPlus.src="../graphics/treenodeplus.gif"; var imgMinus = new Image(); imgMinus.src="../graphics/treenodeminus.gif"; //父节点展开事件 function expandCollapse(el) { //如果父节点有字节点（class 属性为treeSubnodesHidden），展开所有子节点 if (el.className!= "treeNode"){ return; //判断父节点是否为一个树节点，如果树节点不能展开，请检查是否节点的class属性是否为treeNode } var child; var imgEl;//图片子节点，在树展开时更换图片 for(var i=0; i < el.childNodes.length; i++) { child = el.childNodes[i]; if (child.src) { imgEl = child; } else if (child.className == "treeSubnodesHidden") { child.className = "treeSubnodes";//原来若隐藏，则展开 imgEl.src = imgMinus.src;//更换图片 break; } else if (child.className == "treeSubnodes") { child.className = "treeSubnodesHidden";//原来若展开，则隐藏 imgEl.src = imgPlus.src;//更换图片 break; } } } //子节点点击事件，设置选中节点的样式 function clickAnchor(el) { selectNode(el.parentNode); el.blur(); } function selectNode(el) { if (treeSelected != null) { setSubNodeClass(treeSelected, 'A', 'treeUnselected'); } setSubNodeClass(el, 'A', 'treeSelected'); treeSelected = el; } function setSubNodeClass(el, nodeName, className) { var child; for (var i=0; i < el.childNodes.length; i++) { child = el.childNodes[i]; if (child.nodeName == nodeName) { child.className = className; break; } } } </script> </body> </html>