train::coding PHP Method

    public static function coding($str)
    {
        $charset = mb_detect_encoding($str, array('ASCII', 'GB2312', 'GBK', 'UTF-8'));
        if ($charset != 'UTF-8') {
            $str = iconv('UTF-8', $charset . '//IGNORE', $str);
        }
        return $str;
    }