public static List <GetCourse> GetgridData() { gridData.Clear(); wcf.parti.Service1 _parti = new wcf.parti.Service1(); partiDB.RootObject rootObject = new partiDB.RootObject(); if (gridData.Count == 0) { string json_str = _parti.GetCourse(); if (json_str == "e0")//code error { MessageBox.swalModal(_Page, "error", "e0:ລະບົບຂັດຂ້ອງຕິດຕໍ່ຜູ້ເບີ່ງແຍ່ງດ່ວນ.", ""); } else if (json_str == "e1")//no data found { MessageBox.swalModal(_Page, "info", "e1:ບໍ່ມີຂໍ້ມູນທີ່ຈະສະແດງ.", ""); } else if (json_str == "e2")//can't connect databbase { MessageBox.swalModal(_Page, "warning", "e2:ບໍ່ສາມາດເຊື່ອມຕໍ່ຖານຂໍ້ມູນໄດ້.", ""); } else { rootObject = JsonConvert.DeserializeObject <partiDB.RootObject>(json_str); foreach (var vl in rootObject.GetCourse) { gridData.Add(new GetCourse(vl.id, vl.name, vl.description)); } } } return(gridData); }