public ActionResult Edit(Store store)
 {
     try
     {
         if (ModelState.IsValid)
         {
             db.Entry(store).State = EntityState.Modified;
             db.SaveChanges();
             return RedirectToAction("Index");
         }
     }
     catch (Exception)
     {
         ModelState.AddModelError("", "Error occurred while Modifying store, please check your information!");
     }
     //用户更新失败,提醒用户,并请求重新修改
     SelectList regions = new SelectList(db.Regions.ToList(), "RegionID", "RegionName", store.Region.RegionID);
     ViewBag.RegionID = regions;
     return View(store);
 }
 public ActionResult Create(Store store)
 {
     try
     {
         if (ModelState.IsValid)
         {
             db.Stores.Add(store);
             db.SaveChanges();
             return Redirect("Index");
         }
     }
     catch (Exception e)
     {
         ModelState.AddModelError("", "Error occurred while Creating store, please check your information!" + e.Message);
     }
     //用户创建失败,提醒用户,并请求重新输入信息
     SelectList regions = new SelectList(db.Regions.ToList(), "RegionID", "RegionName", db.Regions.ToList()[0]);
     ViewBag.RegionID = regions;
     return View(store);
 }