php的汉字转换：Unicode(UTF8)至GBK

php的汉字转换一直是比较麻烦的事

该类内置了四个过滤"&#[dec];","&#x[hex];","%u[hex]","utf8转换"
方便用户的使用，同时也可自定义过滤进行自己喜欢的操作

qswhU.php 从这里下载
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){
  $arr=array("/&#(\w+);/iU","/((%\w\w)+)/i","/%u(\w{4,5})/iU");
  if(is_integer($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 $chr1=hexdec(substr($matches[0][$i],1));
$arr=array("f0","e0","c0","0");
for($j=0;$jhexdec($arr[$j]))break;
    $chr=hexdec(substr($matches[0][$i],1))-hexdec($arr[$j]);
    while(++$j $str=dechex($chr);
if(strlen($str)==4){
$p=hexdec(substr($str,0,2))-0x4d;
$q=hexdec(substr($str,2))*4;
$ret.=chr(hexdec(substr($this->qswhData[$p],$q,2)));
     $ret.=chr(hexdec(substr($this->qswhData[$p],$q+2,2)));
    }else
     $ret.=chr(hexdec($str));
   }
  }
  else{ 
   if(strtolower($str[0])=="x")
    $str=substr($str,1);
   else
    if(strlen($str)!=4)$str=dechex($str);
    
   if(strlen($str)==4){
    $p=hexdec(substr($str,0,2))-0x4d;
    $q=hexdec(substr($str,2))*4;
    $ret.=chr(hexdec(substr($this->qswhData[$p],$q,2)));
    $ret.=chr(hexdec(substr($this->qswhData[$p],$q+2,2)));
   }else
    $ret.=chr(hexdec($str));
  }
  return $ret;
 }
 
 
}

使用范例

$qswh=new qswhU("qswhU.php");//如果文件名是qswhU.php,可省参数
echo "