public GiaoDichGuiTien HuyGiaoDich(GiaoDichGuiTien gd)
 {
     try
     {
         if (ModelState.IsValid && gd != null)
         {
             var giaoDich = db.GiaoDichGuiTiens.Where(a => a.MaGD == gd.MaGD).FirstOrDefault();
             if (giaoDich != null)
             {
                 giaoDich.TrangThai = TrangThaiGiaoDich.Huy;
                 db.SaveChanges();
                 return(gd);
             }
         }
     }
     catch (Exception ex)
     {
         Console.WriteLine(ex.Message);
     }
     return(null);
 }
        public GiaoDichGuiTien ThemGiaoDich(GiaoDichGuiTien gd)
        {
            try
            {
                if (ModelState.IsValid && gd != null)
                {
                    gd.MaGD      = AppUtils.GetTransactionID(LoaiGiaoDich.GuiTien, DateTime.Now);
                    gd.TrangThai = TrangThaiGiaoDich.DangXuLy;
                    gd.NgayTao   = DateTime.Now;

                    db.GiaoDichGuiTiens.Add(gd);
                    db.SaveChanges();
                    return(gd);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            return(null);
        }