这是一款js实现无限级树形下拉导航菜单，简洁实用，用到一个已封装好的JS类，有用的大家借鉴一下。
运行效果截图如下：
在线演示地址如下：
具体代码如下：
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'+c1:c1;} break; case 'remove': var rep=o.className.match(' '+c1)?' '+c1:c1; o.className=o.className.replace(rep,''); break; case 'check': var found=false; var temparray=o.className.split(' '); for(var i=0;i<temparray.length;i++){ if(temparray[i]==c1){found=true;} } return found; break; } }, safariClickFix:function(){ return false; } } DOMhelp.addEvent(window, 'load', DOMhelp.init, false); </script> <script type="text/javascript"> <!-- sn={ dynamicClass:'dyn', showClass:'show', parentClass:'parent', openClass:'open', navID:'nav', init:function(){ var triggerLink; if(!document.getElementById || !document.createTextNode){return;} var nav=document.getElementById(sn.navID); if(!nav){return;} DOMhelp.cssjs('add',nav,sn.dynamicClass); var nested=nav.getElementsByTagName('ul'); for(var i=0;i<nested.length;i++){ triggerLink=nested[i].parentNode.getElementsByTagName('a')[0]; DOMhelp.cssjs('add',triggerLink.parentNode,sn.parentClass); DOMhelp.addEvent(triggerLink,'click',sn.changeSection,false); triggerLink.onclick=DOMhelp.safariClickFix; if(nested[i].parentNode.getElementsByTagName('strong').length>0){ DOMhelp.cssjs('add',triggerLink.parentNode,sn.openClass); DOMhelp.cssjs('add',nested[i],sn.showClass); } } }, changeSection:function(e){ var t=DOMhelp.getTarget(e); var firstList=t.parentNode.getElementsByTagName('ul')[0]; if(DOMhelp.cssjs('check',firstList,sn.showClass)){ DOMhelp.cssjs('remove',firstList,sn.showClass) DOMhelp.cssjs('swap',t.parentNode,sn.openClass,sn.parentClass); } else { DOMhelp.cssjs('add',firstList,sn.showClass) DOMhelp.cssjs('swap',t.parentNode,sn.openClass,sn.parentClass); } DOMhelp.cancelClick(e); } } DOMhelp.addEvent(window,'load',sn.init,false); --> </script> <h2>js实现无限级树形导航列表</h2> <ul> <li><a href="#">主页</a></li> <li><a href="#">产品</a> <ul> <li><a href="#">大类别一</a> <ul> <li><a href="#">小类别一</a> <ul> <li><a href="#">次类别一</a></li> <li><a href="#">次类别二</a></li> </ul> </li> <li><a href="#">小类别二</a></li> </ul> </li> <li><a href="#">大类别二</a></li> <li><a href="#">大类别三</a> <ul> <li><a href="#">小类别一</a></li> <li><a href="#">小类别二</a></li> </ul> </li> </ul> </li> <li><a href="#">服务</a> <ul> <li><a href="#">大类别一</a></li> <li><a href="#">大类别二</a></li> <li><a href="#">大类别三</a></li> </ul> </li> <li><a href="#">合作</a></li> <li><a href="#">关于我们</a> <ul> <li><a href="#">大类别一</a> <ul> <li><a href="#">小类别一</a></li> <li><a href="#">小类别二</a></li> </ul> </li> <li><a href="#">大类别二</a> <ul> <li><a href="#">小类别一</a></li> <li><a href="#">小类别二</a></li> </ul> </li> <li><a href="#">大类别三</a> <ul> <li><a href="#">小类别一</a></li> <li><a href="#">小类别二</a></li> </ul> </li> <li><a href="#">大类别四</a></li> </ul> </li> <li><a href="#">联系我们</a> <ul> <li><a href="#">大类别一</a></li> <li><a href="#">大类别二</a></li> </ul> </li> </ul>