function stringLength($string){
$re[‘utf-8‘] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";
preg_match_all($re[‘utf-8‘], $string, $match);
return count($match[0]);
}
原文：http://ouyangjun.blog.51cto.com/10284323/1838030