public ActionResult SuaPromotion(Promotion pro, PromotionDetail detail) { if (ModelState.IsValid) { QuanLy ql = new QuanLy(); ql.UpdatePromotion(pro, detail); __db.Entry(pro).State = EntityState.Modified; __db.SaveChanges(); __db.Entry(detail).State = EntityState.Modified; __db.SaveChanges(); ViewBag.IDPromotion = new SelectList(__db.Brands, "ID", "Name", pro.ID); return(RedirectToAction("Promotion")); } return(View(pro)); }