php逐一处理字符串里的中文字符函数
						
						
																											将字符串中中文字符编码后16进制字符小写:
function urlencode_lower($str) {
 $outStr = '';
 $len = strlen($str);
 for($i = 0; $i < $len; $i++) {
  if(ord($str{$i}) > 127) {
   $ch = substr($str, $i, 2);
   $p = 1;
   $outStr .= strtolower(urlencode($ch));
  } else {
   $ch = substr($str, $i, 1);
   $p = 0;
   $outStr .= urlencode($ch);
  }
  $i += $p;
 }
 return $outStr;
}
echo urlencode_lower('妈妈咪'); //%c2%e8%c2%e8%df%e4