php的汉字转换：Unicode(UTF8)至GBK

P>秋水无恨 GBK Unicode UTF8 汉字 转换
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){
$arr=array("/&#(w+);/iU","/((%ww)+)/i","/%u(w{4,5})/iU");
if(is_integer($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;