public static List <GetProvince> GetProvinces() { listProvince.Clear(); wcf.parti.Service1 _parti = new wcf.parti.Service1(); partiDB.RootObject rootObject = new partiDB.RootObject(); if (listProvince.Count == 0) { string json_str = _parti.GetProvince(); 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 database { MessageBox.swalModal(_Page, "warning", "e2:ບໍ່ສາມາດເຊື່ອມຕໍ່ຖານຂໍ້ມູນໄດ້.", ""); } else { rootObject = JsonConvert.DeserializeObject <partiDB.RootObject>(json_str); foreach (var vl in rootObject.GetProvince) { listProvince.Add(new GetProvince(vl.p_id, vl.p_name)); } } } return(listProvince); }