php的漢字轉換：Unicode(UTF8)至GBK

P>秋水無恨 GBK Unicode UTF8 漢字 轉換
php的漢字轉換一直是比較麻煩的事
該類內置了四個過濾"&#[dec];","&#x[hex];","%u[hex]","utf8轉換"
方便用戶的使用，同時也可自定義過濾進行自己喜歡的操作
qswhU.php 從這裡下載
http://www.blueidea.com/user/qswh/qswhU.zip
class qswhU{
 var $qswhData;
 function qswhU($filename="qswhU.php"){
  $this->qswhData=file($filename);
 }
 
 function decode($str,$pattern=0){
  $arr=array("/&#(w+);/iU","/((%ww)+)/i","/%u(w{4,5})/iU");
  if(is_integer($pattern)){
      if($pattern>=count($arr))die("Invalid Function");
      $pattern=$arr[$pattern];
  }
  return preg_replace_callback($pattern,array($this,"u2gb"),$str);
 }
 
 function u2gb($arr){
  /******(qiushuiwuhen 2002-8-15)******/
  $ret="";$str=$arr[1];
  if(preg_match_all("/%w{2}/",$str,$matches)){
     for($i=0;$i<count($matches[0]);$i++){
      $chr1=hexdec(substr($matches[0][$i],1));
      $arr=array("f0","e0","c0","0");
      for($j=0;$j<count($arr);$j++)if($chr1>hexdec($arr[$j]))break;
      $chr=hexdec(substr($matches[0][$i],1))-hexdec($arr[$j]);
      while(++$j<count($arr))$chr=$chr*0x40+(hexdec(substr($matches[0][++$i],1))-0x80);
      $str=dechex($chr);
      if(strlen($str)==4){
     $p=hexdec(substr($str,0,2))-0x4d;
     $q=hexdec(substr($str,2))*4;