//如果乱码的话更改header函数

<?php //header('Content-type: text/html;charset=utf-8');
class xmlarray
{

private $xml = '';//用于读取xml的变量
    private $data;    //生成的xml
    private $dom_tree;//xml目录树
/**
   __construct仅用于读取xml
*/
    function __construct($xml="")
    {
   if(empty($xml))
   {
    return null;
   }
   //$this->xml = $xml;
   else
   {
             $this->loadxml($xml);
   }
    }
/**
     装载要处理的xml文档也可以在初始化时装载
*/
public function loadxml($filepath)
{  
      $handle = @fopen($filepath,"r");

while (!feof($handle)&&$handle)
   {
              $xml_data .= fgets($handle, 4096);
         }
   $this->xml=$xml_data;
}
/**
     处理xml文档
*/
    private function _struct_to_array($values, &$i)
    {
   $child = array();
   if (isset($values[$i]['value'])) array_push($child, $values[$i]['value']);

while ($i++ < count($values))
   {
    switch ($values[$i]['type'])
    {
     case 'cdata':
      array_push($child, $values[$i]['value']);
      break;

case 'complete':
      $name = $values[$i]['tag'];
      if(!empty($name))
      {
       $child[$name]= ($values[$i]['value'])?($values[$i]['value']):'';
       if(isset($values[$i]['attributes']))
       {
        $child[$name] = $values[$i]['attributes'];
       }
      }
      break;

case 'open':
      $name = $values[$i]['tag'];
      $size = isset($child[$name]) ? sizeof($child[$name]) : 0;
      $child[$name][$size] = $this->_struct_to_array($values, $i);
     break;

case 'close':
      return $child;
      break;
    }
   }
   return $child;
    }
/**
    处理xml文档，实际调用 _struct_to_array（）处理
*/
    public function xml2array()
    {
        $xml    =& $this->xml;
        $values = array();
        $index = array();
        $array = array();
        $parser = xml_parser_create();
        xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1);
        xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
        xml_parse_into_struct($parser, $xml, $values, $index);

xml_parser_free($parser);
        $i = 0;
        $name = $values[$i]['tag'];
        $array[$name] = isset($values[$i]['attributes']) ? $values[$i]['attributes'] : '';
        $array[$name] = $this->_struct_to_array($values, $i);
        return $array;
    }

//以下为将数组转换成xml的代码 使用dom
        /**
     读取数组
         */
        public function array2xml($array){
            if(!is_array($array)){
                throw new Exception('array2xml requires an array', 1);
                unset($array);
            }
            if(!count($array)){
                throw new Exception('array is empty', 2);
                unset($array);
            }
           
            $this->data = new DOMDocument();         
            $this->dom_tree = $this->data->createElement('result');//默认要标签
            $this->data->appendChild($this->dom_tree);
            $this->recurse_node($array, $this->dom_tree);
        }
       
        /**
             处理数组为xml
         */
        private function recurse_node($data, $obj){
            $i = 0;
            foreach($data as $key=>$value){
                if(is_array($value)){
                    //recurse if neccisary
                    $sub_obj[$i] = $this->data->createElement($key);//创建标签
                    $obj->appendChild($sub_obj[$i]); //将标签加入到$obj标签下
                    $this->recurse_node($value, $sub_obj[$i]); //将值加入此标签下
                } elseif(is_object($value)) {
                    //no object support so just say what it is
                   
$sub_obj[$i] = $this->data->createElement($key, 'Object: "' .
$key . '" type: "' . get_class($value) . '"');
                    $obj->appendChild($sub_obj[$i]);
                } else {
                    //straight up data, no weirdness
                    $sub_obj[$i] = $this->data->createElement($key, $value);
      //如果是最后的节点，将节点名和内容创建
                    $obj->appendChild($sub_obj[$i]);
                }
                $i++;
            }
        }
       
        /**
　　　　　　　将数组保存成xml文件
         */
        public function saveXML($arraytoxml="")
   {
    if($arraytoxml=="")
    {
     $out = iconv("gbk","utf-8","请输入将要保存的文件名");
     echo "<script>alert('$out')</script>";
    }
    else
    {
                 return $this->data->save($arraytoxml);
    }
        }
}
?>

将数组转换成xml文件
<?php
   $test = array(
        'one'=>'number',
        'two'=> array(
            'c'=>1,
            'd'=>2,
            'e'=>3,
            'f'=>4
        ),
        'three'=>'alpha'
    );
   /*创建对象*/
   $xmlObj= new xmlarray();
   /*转换*/
   $xml = $xmlObj->array2xml($test);
   /*输出保存*/
   $xmlObj->saveXML("a.xml");
   ?>

将xml解析为数组输出
<?php
   /*创建对象*/
   $xmlObj    = new xmlarray();
   /*装载*/
   $xml = $xmlObj->loadxml("a.xml");
   /*转换*/
   $data=$xmlObj->xml2array();
   /*显示*/
   print_r($data);
?>