<?xml version="1.0" encoding="ISO-8859-1"?>

 <root>

     <item id="Title" aa="ddd"><![CDATA[Discuz! Style]]></item>

     <item id="Data" aa="ddd">

         <item id="name" aa="ddd"><![CDATA[默认风格]]></item>

         <item id="templateid" aa="ddd"><![CDATA[]]></item>

         <item id="tplname" aa="ddd"><![CDATA[默认模板套系]]></item>

         <item id="directory" aa="ddd"><![CDATA[./template/default]]></item>

         <item id="copyright" aa="ddd"><![CDATA[康盛创想（北京）科技有限公司]]></item>

         <item id="style" aa="ddd">

             <item id="smfont" aa="ddd"><![CDATA[Arial]]></item>

             <item id="threadtitlefontsize" aa="ddd"><![CDATA[14px]]></item>

             <item id="threadtitlefont" aa="ddd"><![CDATA[Tahoma,'Microsoft Yahei','Simsun']]></item>

             <item id="smfontsize" aa="ddd"><![CDATA[0.83em]]></item>

             <item id="tabletext" aa="ddd"><![CDATA[#444]]></item>

             <item id="midtext" aa="ddd"><![CDATA[#666]]></item>

             <item id="lighttext" aa="ddd"><![CDATA[#999]]></item>

             <item id="link" aa="ddd"><![CDATA[#333]]></item>

             <item id="highlightlink" aa="ddd"><![CDATA[#369]]></item>

             <item id="noticetext" aa="ddd"><![CDATA[#F26C4F]]></item>

             <item id="bgcolor" aa="ddd"><![CDATA[#FFF background.png repeat-x 0 0]]></item>

             <item id="msgfontsize" aa="ddd"><![CDATA[14px]]></item>

             <item id="sidebgcolor" aa="ddd"><![CDATA[ vlineb.png repeat-y 0 0]]></item>

             <item id="headerborder" aa="ddd"><![CDATA[]]></item>

             <item id="headerbgcolor" aa="ddd"><![CDATA[]]></item>

             <item id="inputborderdarkcolor" aa="ddd"><![CDATA[#848484]]></item>

             <item id="stypeid" aa="ddd"><![CDATA[]]></item>

             <item id="inputbg" aa="ddd"><![CDATA[#FFF]]></item>

             <item id="commonborder" aa="ddd"><![CDATA[#CDCDCD]]></item>

             <item id="commonbg" aa="ddd"><![CDATA[#F2F2F2]]></item>

             <item id="specialborder" aa="ddd"><![CDATA[#C2D5E3]]></item>

             <item id="specialbg" aa="ddd"><![CDATA[#E5EDF2]]></item>

             <item id="dropmenuborder" aa="ddd"><![CDATA[#DDD]]></item>

             <item id="floatmaskbgcolor" aa="ddd"><![CDATA[#000]]></item>

             <item id="dropmenubgcolor" aa="ddd"><![CDATA[#FEFEFE]]></item>

             <item id="floatbgcolor" aa="ddd"><![CDATA[#FFF]]></item>

             <item id="lightlink" aa="ddd"><![CDATA[#FFF]]></item>

             <item id="menuhoverbgcolor" aa="ddd"><![CDATA[#005AB4 nv_a.png no-repeat 50% -33px]]></item>

             <item id="titlebgcolor" aa="ddd"><![CDATA[#E5EDF2 titlebg.png repeat-x 0 0]]></item>

             <item id="fontsize" aa="ddd"><![CDATA[12px/1.5]]></item>

             <item id="font" aa="ddd"><![CDATA[Tahoma,'Microsoft Yahei','Simsun']]></item>

             <item id="styleimgdir" aa="ddd"><![CDATA[]]></item>

             <item id="imgdir" aa="ddd"><![CDATA[]]></item>

             <item id="boardimg" aa="ddd"><![CDATA[logo.png]]></item>

             <item id="available" aa="ddd"><![CDATA[]]></item>

             <item id="headertext" aa="ddd"><![CDATA[#444]]></item>

             <item id="footertext" aa="ddd"><![CDATA[#666]]></item>

             <item id="menubgcolor" aa="ddd"><![CDATA[#2B7ACD nv.png no-repeat 0 0]]></item>

             <item id="menutext" aa="ddd"><![CDATA[#FFF]]></item>

             <item id="menuhovertext" aa="ddd"><![CDATA[#FFF]]></item>

             <item id="wrapbg" aa="ddd"><![CDATA[#FFF]]></item>

             <item id="wrapbordercolor" aa="ddd"><![CDATA[#CCC]]></item>

             <item id="contentwidth" aa="ddd"><![CDATA[630px]]></item>

             <item id="contentseparate" aa="ddd"><![CDATA[#C2D5E3]]></item>

             <item id="inputborder" aa="ddd"><![CDATA[#E0E0E0]]></item>

         </item>

         <item id="version" aa="ddd"><![CDATA[X3.1]]></item>

     </item>

 </root>

     $xml=new DOMDocument();

     $xml->load($file);

        //读出item节点

     $item=$xml->getElementsByTagName("item");

 $xml=new DOMDocument();

 $xml->load($file);

 $item=$xml->getElementsByTagName("item");

 foreach ($item as $key=>$v){

     echo $v->getAttribute("id");//获取属性为id的值

     $v->setAttribute("aa",'ddd');//增加一个新的属性aa

     $v->removeAttribute("aa");//删除属性

 } 

    $xml=new DOMDocument();

    $xml->load($file);

    $node=$xml->documentElement;

    // 添加节点

    $root=$xml->getElementsByTagName('root')->item(0);//获得根节点

    $elem=$xml->createElement("aa","dddd");//添加aa 节点

    $elem_attr=$xml->createAttribute("test");//添加属性

    $elem_attr->value="aaaa";//设置属性的值

    $elem->appendChild($elem_attr);//添加到节点下

    $root->appendChild($elem);//将aa 添加到根节点下

        //删除节点

    $node=$xml->documentElement;

    $item=$xml->getElementsByTagName("item")->item(0);

    $node->removeChild($item);//删掉第一个节点