static public function detectClientType()
    {
        $clientType       = static::PC;
        if (HttpHelper::isMobile()) {
            if (HttpHelper::isWechat()) {
                $clientType = static::WX;
            } elseif (HttpHelper::isAlipay()) {
                $clientType = static::ALIPAY;
            } else {
                $clientType = static::MOBILE;
            }
        }
        
        return $clientType;
    }