Ajax读取XML实现动态下拉导航


            根据客户的需要做一个产品的分类的导航菜单，以前使用ASP递归读取的。速度慢，而且消耗大量服务器资源。干脆改成AJAX+XML。共享出来和大家交流。希望各位能帮忙改进。产品分类的XML文件复制代码 代码如下://id为自身id，pid为父级分类ID  <?xml version="1.0" encoding="UTF-8" ?>  <Proot>         <Item id="1" pid="0">1321系列</Item>         <Item id="2" pid="1">43223系列</Item>  </Proot> js代码复制代码 代码如下:var root;//FireFox不支持selectNodes方法，在网上找到这段代码解决了这个问题。兼容了IE和FireFox. //创建selectNodes方法 if( document.implementation.hasFeature("XPath", "3.0") ) {    // prototying the XMLDocument    XMLDocument.prototype.selectNodes = function(cXPathString, xNode)    {       if( !xNode ) { xNode = this; }        var oNSResolver = this.createNSResolver(this.documentElement)       var aItems = this.evaluate(cXPathString, xNode, oNSResolver,                     XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null)       var aResult = [];       for( var i = 0; i < aItems.snapshotLength; i++)       {          aResult[i] =  aItems.snapshotItem(i);       }       return aResult;    }    // prototying the Element    Element.prototype.selectNodes = function(cXPathString)    {       if(this.ownerDocument.selectNodes)       {          return this.ownerDocument.selectNodes(cXPathString, this);       }       else{throw "For XML Elements Only";}    } } function createXMLHttpRequest() {     if (window.ActiveXObject) {         oXmlHttp = new ActiveXObject("Microsoft.XMLHTTP");     }      else if (window.XMLHttpRequest) {         oXmlHttp = new XMLHttpRequest();     } } function CreateXMLDOM() { createXMLHttpRequest(); oXmlHttp.open( "GET", "XML路径", false ) ; oXmlHttp.send(null) ; root = oXmlHttp.responseXML.documentElement; } CreateXMLDOM() function funCreatePullMenu(passPid,ChildId) { var currentItems = root.selectNodes("//Proot/Item[@pid = " + passPid + "]"); var iItems = currentItems.length; var k=0; if(iItems > 0) {      var pdiv = document.createElement("DIV");   pdiv.id="piv" + passPid;   pdiv.className = "piv" + ChildId;   pdiv.name = "piv" + passPid;   if(passPid>0)   {        pdiv.style.display="none";     document.getElementById("div" + passPid).appendChild(pdiv);   }   else   {     document.getElementById("odiv").appendChild(pdiv);   }   for(var i = 0; i < iItems; i++)   {    var _id = currentItems[i].attributes[0].value;    var newChild = document.createElement("DIV");    newChild.id="div" + _id;    newChild.className = "div" + ChildId;    newChild.name = "div" + _id;    var _v ;    if(CheckPullMenu(_id))    {     _1= _id     _v = "<a href='javascript:showsubmenu(" + _1 + ")'> " +currentItems[i].firstChild.data + "</a>";    }    else    {     _v = "<a href='ProductList.aspx?type=" + _id + "'>"+ currentItems[i].firstChild.data +"</a>";    }    newChild.innerHTML=_v;        document.getElementById("piv" + passPid).appendChild(newChild);    if(CheckPullMenu(_id))    {    funCreatePullMenu(_id,ChildId+1)    }   } } } //检测是否有下级 function CheckPullMenu(passPid) { var currentItems = root.selectNodes("//Proot/Item[@pid = " + passPid + "]"); var iItems = currentItems.length; if(iItems > 0) {   return true; }     else {   return false; } } //显示隐藏层 function showsubmenu(sid) { var whichEl = document.getElementById( "piv" +sid); if (whichEl.style.display == "none")   {            whichEl.style.display="block";   } else   {      whichEl.style.display="none";   } } 使用方法：在网页中加入"<div id="odiv"></div>"。在body加入onload="funCreatePullMenu(0,0)"最终效果：screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor='hand'; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" onclick="if(!this.resized) {return true;} else {window.open('/upload/200722821450856.gif');}" alt="" src="http://files.zwyuanma.com/upload/200722821450856.gif" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" border=0>可以在代码中增加定义CSS。达到更好的效果。原发于：http://www.23mo.com/blog/article.asp?id=16使用方法：在网页中加入"<div id="odiv"></div>"。在body加入onload="funCreatePullMenu(0,0)"最终效果：screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor='hand'; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" onclick="if(!this.resized) {return true;} else {window.open('/upload/200722821450856.gif');}" alt="" src="http://files.zwyuanma.com/upload/200722821450856.gif" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" border=0>可以在代码中增加定义CSS。达到更好的效果。原发于：http://www.23mo.com/blog/article.asp?id=16