public String CheckPayooAccount(String username)
        {
            String result = "";
            try
            {
                Credential credential = new Credential();
                credential.APIUsername = ConfigurationManager.AppSettings["APIUsername"];
                credential.APIPassword = ConfigurationManager.AppSettings["APIPassword"];
                credential.APISignature = ConfigurationManager.AppSettings["APISignature"];
                Caller caller = new Caller();
                caller.InitCall(ConfigurationManager.AppSettings["PayooBusinessAPI"], credential,
                    Server.MapPath(@"..\App_Data\Certificates\biz_pkcs12.p12"), "alpe", Server.MapPath(@"..\App_Data\Certificates\payoo_public_cert.pem"));

                CheckPayooAccountRequestType req = new CheckPayooAccountRequestType();
                req.AccountID = username; // agentb2 ; vimp71 | [email protected]

                CheckPayooAccountResponseType res = (CheckPayooAccountResponseType)caller.Call("CheckPayooAccount", req);
                if (res.Ack == AckCodeType.Success)
                {
                    result = "Valid";
                }
                else
                {
                    result = "InValid Account";
                }

            }
            catch (Exception ex)
            {
                result = "False";
                throw ex;
            }
            return result;
        }
        public string RefundAll(int IdDuan)
        {
            string result = "false";

            var dautu = db.EntityDauTus.Where(g => g.IdDuAn == IdDuan).ToList();
            foreach (var item in dautu)
            {
                Credential credential = new Credential();
                credential.APIUsername = ConfigurationManager.AppSettings["APIUsername"];
                credential.APIPassword = ConfigurationManager.AppSettings["APIPassword"];
                credential.APISignature = ConfigurationManager.AppSettings["APISignature"];
                Caller caller = new Caller();
                caller.InitCall(ConfigurationManager.AppSettings["PayooBusinessAPI"], credential,
                    Server.MapPath(@"..\App_Data\Certificates\biz_pkcs12.p12"), "alpe", Server.MapPath(@"..\App_Data\Certificates\payoo_public_cert.pem"));

                UpdateOrderStatusRequestType request = new UpdateOrderStatusRequestType();
                request.NewStatus = OrderStatus.Cancelled;
                request.ShopID = long.Parse(ConfigurationManager.AppSettings["ShopID"]);
                request.UpdateLog = "Dự án kết thúc thất bại.";
                request.OrderID = item.OrderID_Payoo;
                UpdateOrderStatusResponseType response = (UpdateOrderStatusResponseType)caller.Call("UpdateOrderStatus", request);
                if (response.Ack == AckCodeType.Success || response.Ack == AckCodeType.SuccessWithWarning)
                {
                    result = "Refund success";
                }
                else
                {
                    return "Fail";
                }
            }
            return result;
        }