public async Task <IActionResult> Edit(int id, [Bind("DoanId,TourId,DoanTen,DoanNgayDi,DoanNgayVe,DoanChiTiet,DoanGiaTour,NgayTao")] TourDoan tourDoan)
        {
            if (id != tourDoan.DoanId)
            {
                return(NotFound());
            }

            if (ModelState.IsValid)
            {
                try
                {
                    var giaTourHienTai = context.GiaTourHienTai.Where(gtht => gtht.TourId == tourDoan.TourId).Include(gt => gt.Gia).FirstOrDefault();
                    tourDoan.DoanGiaTour = giaTourHienTai.Gia.GiaSoTien;
                    context.Update(tourDoan);
                    await context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!TourDoanExists(tourDoan.DoanId))
                    {
                        return(NotFound());
                    }
                    else
                    {
                        throw;
                    }
                }
                return(RedirectToAction(nameof(Index)));
            }
            ViewData["TourId"] = new SelectList(context.Tour, "TourId", "TourTen", tourDoan.TourId);
            return(View(tourDoan));
        }
        public async Task <IActionResult> Create([Bind("DoanId,TourId,DoanTen,DoanNgayDi,DoanNgayVe,DoanChiTiet,DoanGiaTour,NgayTao")] TourDoan tourDoan)
        {
            if (ModelState.IsValid)
            {
                var giaTourHienTai = context.GiaTourHienTai.Where(gtht => gtht.TourId == tourDoan.TourId).Include(gt => gt.Gia).FirstOrDefault();
                tourDoan.DoanGiaTour = giaTourHienTai.Gia.GiaSoTien;
                context.Add(tourDoan);
                await context.SaveChangesAsync();

                return(RedirectToAction(nameof(Index)));
            }
            ViewData["TourId"] = new SelectList(context.Tour, "TourId", "TourTen", tourDoan.TourId);
            return(View(tourDoan));
        }