PHP：将汉字转换为utf8码

 $str = "这是一个测试";

 function escapeToHex($string, $encoding = "UTF-8") {
  $r_str = "";

  for ($x = 0; $x < mb_strlen($string, $encoding); $x ++) {
   $str = mb_substr($string, $x, 1, $encoding);
   if (strlen($str) > 1) {
    $r_str .="%u".strtoupper(bin2hex(mb_convert_encoding($str, "UCS-2", $encoding)));
   } else {
    $r_str .="%". strtoupper(bin2hex($str));
   }
  }
  return $r_str;
 }
 $str = preg_replace("/(%u)(\w{4})/i","&#x$2;",escapeToHex($str));
 print $str;
?>