本文实例讲述了JavaScript+CSS无限极分类效果完整实现方法。分享给大家供大家参考，具体如下：
CSS样式：
a {text-decoration:none;}a,a:visited {color:#000;background:inherit;}body {margin:0;padding:20px;font:12px tahoma,宋体,sans-serif;}dt {font-size:22px;font-weight:bold;margin:0 0 0 15px;}dd {margin:0 0 0 15px;}h4 {margin:0;padding:0;font-size:18px;text-align:center;}p {margin:0;padding:0 0 0 18px;}p a,p a:visited {color:#00f;background:inherit;}/*CNLTreeMenu Start*/.CNLTreeMenu img.s {cursor:pointer;vertical-align:middle;}.CNLTreeMenu ul {padding:0;}.CNLTreeMenu li {list-style:none;padding:0;}.Closed ul {display:none;}.Child img.s {background:none;cursor:default;}#CNLTreeMenu1 ul {margin:0 0 0 17px;}#CNLTreeMenu1 img.s {width:20px;height:15px;}#CNLTreeMenu1 .Opened img.s {background:url(skin1/opened.gif) no-repeat 0 0;}#CNLTreeMenu1 .Closed img.s {background:url(skin1/closed.gif) no-repeat 0 0;}#CNLTreeMenu1 .Child img.s {background:url(skin1/child.gif) no-repeat 3px 5px;}#CNLTreeMenu2 ul {margin:0 0 0 17px;}#CNLTreeMenu2 img.s {width:17px;height:15px;}#CNLTreeMenu2 .Opened img.s {background:url(skin2/opened.gif) no-repeat 4px 6px;}#CNLTreeMenu2 .Closed img.s {background:url(skin2/closed.gif) no-repeat 3px 6px;}#CNLTreeMenu2 .Child img.s {background:url(skin2/child.gif) no-repeat 3px 5px;}#CNLTreeMenu3 ul {margin:0 0 0 17px;}#CNLTreeMenu3 img.s {width:34px;height:18px;}#CNLTreeMenu3 .Opened img.s {background:url(skin3/opened.gif) no-repeat 0 1px;}#CNLTreeMenu3 .Closed img.s {background:url(skin3/closed.gif) no-repeat 0 1px;}#CNLTreeMenu3 .Child img.s {background:url(skin3/child.gif) no-repeat 13px 2px;}/*CNLTreeMenu End*//*Temp CSS for View Demo*/#CNLTreeMenu1,#CNLTreeMenu2,#CNLTreeMenu3 {float:left;width:249px;border:1px solid #99BEEF;background:#D2E4FC;color:inherit;margin:3px;padding:3px;}#CNLTreeMenu1,#CNLTreeMenu2 {padding-bottom:15px;}.ViewCode { clear:both; border:1px solid #FFB900;background:#FFFFCC;color:inherit;margin:3px;padding:3px;}.ViewCode h6 {color:#00f;} JavaScript代码：
function Ob(o){ var o=document.getElementById(o)?document.getElementById(o):o; return o;}function Hd(o) { Ob(o).style.display="none";}function Sw(o) { Ob(o).style.display="";}function ExCls(o,a,b,n){ var o=Ob(o); for(i=0;i<n;i++) {o=o.parentNode;} o.className=o.className==a?b:a;}function CNLTreeMenu(id,TagName0) { this.id=id; this.TagName0=TagName0==""?"li":TagName0; this.AllNodes = Ob(this.id).getElementsByTagName(TagName0); this.InitCss = function (ClassName0,ClassName1,ClassName2,ImgUrl) { this.ClassName0=ClassName0; this.ClassName1=ClassName1; this.ClassName2=ClassName2; this.ImgUrl=ImgUrl || "css/s.gif"; this.ImgBlankA ="<img src=/""+this.ImgUrl+"/" class=/"s/" onclick=/"ExCls(this,'"+ClassName0+"','"+ClassName1+"',1);/" this.ImgBlankB ="<img src=/""+this.ImgUrl+"/" class=/"s/" />"; for (i=0;i<this.AllNodes.length;i++ ) { this.AllNodes[i].className==""?this.AllNodes[i].className=ClassName1:""; this.AllNodes[i].innerHTML=(this.AllNodes[i].className==ClassName2?this.ImgBlankB:this.ImgBlankA)+this.AllNodes[i].innerHTML; } } this.SetNodes = function (n) { var sClsName=n==0?this.ClassName0:this.ClassName1; for (i=0;i<this.AllNodes.length;i++ ) { this.AllNodes[i].className==this.ClassName2?"":this.AllNodes[i].className=sClsName; } }} HTML页面：
<!--CNLTreeMenu Start:--><div class="CNLTreeMenu" id="CNLTreeMenu1"><h4>CNL Tree Menu1</h4><p><a id="AllOpen_1" href="#" onclick="MyCNLTreeMenu1.SetNodes(0);Hd(this);Sw('AllClose_1');">全部展开</a><a id="AllClose_1" href="#" onclick="MyCNLTreeMenu1.SetNodes(1);Hd(this);Sw('AllOpen_1');" style="display:none;">全部折叠</a></p><ul> <li class="Opened"><a href="http://www.vevb.com">JB51.Net</a> <ul> <li><a href="#1">技术区</a> <ul> <li><a href="#">网页技术</a> <ul> <li class="Child"><a href="#">JavaScript</a></li><!--Child Node--> <li class="Child"><a href="#">HTML/XHTML/CSS</a></li> <li class="Child"><a href="#">Ajax</a></li> <li class="Child"><a href="#">网页制作工具</a></li> <li class="Child"><a href="#">设计/图形</a></li> <li class="Child"><a href="#">Flash/多媒体</a></li> <li class="Child"><a href="#">VML/Web3D</a></li> </ul></li><!--Sub Node 3--> <li><a href="#">Web编程</a> <ul> <li class="Child"><a href="#">Java</a></li><!--Child Node--> <li class="Child"><a href="#">.Net</a></li> <li class="Child"><a href="#">ASP/VBScript</a></li> <li class="Child"><a href="#">PHP</a></li> <li class="Child"><a href="#">Perl/Python</a></li> <li class="Child"><a href="#">Web综合/开源</a></li> </ul></li><!--Sub Node 3--> <li><a href="#">数据库</a> <ul> <li class="Child"><a href="#">Access/SQLServer</a></li><!--Child Node--> <li class="Child"><a href="#">MySQL/PostgreSQL</a></li> <li class="Child"><a href="#">Oracle/DB2/Sybase</a></li> </ul></li><!--Sub Node 3--> <li><a href="#">服务器</a> <ul> <li class="Child"><a href="#">Windows/IIS</a></li><!--Child Node--> <li class="Child"><a href="#">Unix/Linux/Apache</a></li> <li class="Child"><a href="#">应用服务器</a></li> </ul></li><!--Sub Node 3--> </ul></li><!--Sub Node 2--> <li><a href="#1">二级目录</a> <ul> <li><a href="#">三级目录</a> <ul> <li><a href="#">四级目录</a> <ul> <li><a href="#">五级目录</a> <ul> <li><a href="#"></a> <ul> <li><a href="#">第n级目录</a> <ul> <li class="Child"><a href="#">叶结点1</a></li><!--Child Node--> <li class="Child"><a href="#">叶结点2</a></li> <li class="Child"><a href="#">叶结点3</a></li> </ul></li><!--Sub Node n --> </ul></li><!--Sub Node 6 --> </ul></li><!--Sub Node 5 --> </ul></li><!--Sub Node 4--> </ul></li><!--Sub Node 3--> </ul></li><!--Sub Node 2--> <li><a href="#1">二级目录</a> <ul> <li><a href="#">三级目录</a> <ul> <li><a href="#">四级目录</a> <ul> <li><a href="#">五级目录</a> <ul> <li><a href="#"></a> <ul> <li><a href="#">第n级目录</a> <ul> <li class="Child"><a href="#">叶结点1</a></li><!--Child Node--> <li class="Child"><a href="#">叶结点2</a></li> <li class="Child"><a href="#">叶结点3</a></li> </ul></li><!--Sub Node n --> </ul></li><!--Sub Node 6 --> </ul></li><!--Sub Node 5 --> </ul></li><!--Sub Node 4--> </ul></li><!--Sub Node 3--> </ul></li><!--Sub Node 2--> </ul></li><!--Sub Node 1 --></ul></div><!-- CNLTreeMenu --><!--CNLTreeMenu1 End!--> 希望本文所述对大家JavaScript程序设计有所帮助。
