/**
* 生成sell标签内容
*
* @param int $cost 需要的积分
* @param stirng $str 隐藏的内容
* @param object $config ubb转换配置
* @return string
*/
public static function createSell($length, $cost, $str, $config)
{
self::$_hide = true;
list($cost, $credit) = explode(',', $cost);
$creditBo = PwCreditBo::getInstance();
$cname = isset($creditBo->cType[$credit]) ? $creditBo->cType[$credit] : current($creditBo->cType);
return array('<span>[以下帖子售价 ' . $cost . ' ' . $cname . '，购买后显示内容]</span>', 16);
}
