截图多余字符，中英文，避免截取中文乱码

截图多余字符，中英文都可以，避免截取中文结尾 ？？ 乱码！！

function utf8_strlen($string = null) {
				// 将字符串分解为单元
				preg_match_all('/./us', $string, $match);
				// 返回单元个数
				return count($match[0]);
			}
		   	function sub_content($content, $length){
				$len = utf8_strlen($content);
				for($i = 0 ; $i 					$arr[$i] = mb_substr($content,$i,1,'utf-8');
				}
				$get_length = 0;
				$result = '';
				foreach($arr as $code){
					$result .= $code;

					if(strlen($code) > 1){
						$get_length += 2;
					}else{
						$get_length += 1;
					}
					if($get_length >= $length){
						break;
					}
				}
				return $result;
			}
 echo   sub_content($rows["Description"],18);



/**
 * 字符串截取，支持中文和其他编码
 * @param string $str
 * @param int $start
 * @param int $length
 * @param string $charset
 * @param boolean $suffix
 * @return string
 */
function w_substr($str, $start = 0, $length, $charset = "utf-8", $suffix = TRUE) {
	$suffix_str = $suffix ? '…' : '';
	if(function_exists('mb_substr')) {
		return mb_substr($str, $start, $length, $charset) . $suffix_str;
	} elseif(function_exists('iconv_substr')) {
		return iconv_substr($str, $start, $length, $charset) . $suffix_str;
	} else {
		$pattern = array();
		$pattern['utf-8'] = '/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/';
		$pattern['gb2312'] = '/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/';
		$pattern['gbk'] = '/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/';
		$pattern['big5'] = '/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/';
		preg_match_all($pattern[$charset], $str, $matches);
		$slice = implode("", array_slice($matches[0], $start, $length));
		return $slice . $suffix_str;
	}
}