public IHttpActionResult GetAddProduct(string _IdOL, string _IdP) { int _idol = int.Parse(_IdOL); int _idp = int.Parse(_IdP); OrderLineSet orderL = db.OrderLineSet.Find(_idol); Product product = db.Product.Find(_idp); GenericImplement <OrderLineSet> _GenericMethod = new GenericImplement <OrderLineSet>(); if (orderL == null) { return(NotFound()); } if (orderL.Product == product) { orderL.Quantity = orderL.Quantity + 1; _GenericMethod.Update(orderL); _GenericMethod.SaveAll(); } else { OrderLineSet _orderLine = (OrderLineSet)GetCreate_orderLine("" + orderL.Order_Id); _orderLine.Quantity = 1; _orderLine.Product = product; _GenericMethod.SaveAll(); System.Xml.Serialization.XmlSerializer x1 = new System.Xml.Serialization.XmlSerializer(_orderLine.GetType()); var _StringWriter1 = new StringWriter(); XmlWriter _Writer1 = XmlWriter.Create(_StringWriter1); x1.Serialize(_Writer1, _orderLine); string _Xml1 = _StringWriter1.ToString(); return(Ok(_Xml1)); } System.Xml.Serialization.XmlSerializer x2 = new System.Xml.Serialization.XmlSerializer(orderL.GetType()); var _StringWriter2 = new StringWriter(); XmlWriter _Writer2 = XmlWriter.Create(_StringWriter2); x2.Serialize(_Writer2, orderL); string _Xml2 = _StringWriter2.ToString(); return(Ok(_Xml2)); }