MVC posting with a list of objects, collection is empty

See also questions close to this topic

• Enum form to controller

  Trying to get the value from an enum dropdown menu to a controller.

  @using (Html.BeginForm("Update"))
  {
      <div class="form-group">
          @Html.DropDownList("fruit", EnumHelper.GetSelectList(typeof(TestApp.Models.FruitType)), "Select")
      </div>
      <button type="submit" class="btn btn-primary">Select</button>
  }
  

  In the controller i want to be able to use the value posted by the form.

  public ActionResult Index()
  {
     return View();
  }
  
  [HttpPost]
  public ActionResult Update(FruitType fruitType)
  {
     FruitType type;
     if(fruitType == 0) 
          type = FruitType.Banana;
     if(fruitType == 1) 
          type = FruitType.Apple;
     if(fruitType == 2) 
          type = FruitType.Orange;
     if(fruitType == 3) 
          type = FruitType.Pear;
  
     sendRequest(fruitType);
  
     return View("Index");
  }
  

  Nothing seems to happen when the form is posted, can see the value being sent in the header.

  Is there some other way this should be handled in the controller?
• Duplicate row inserted after user submits a form - MVC Entity framework

  I am facing a weird situation. I am trouble shooting an issue where a User was facing an error due to more than one record found for the given criteria (invalidOperationException: Sequence contains more than one element.). Upon checking the database records, there are more than one row inserted when user clicks on "Save" action which submits the form. But I am not able to reproduce this issue from my end, I have tried submitting form multiple times by multiple clicks but still data insertion is working fine without creating any duplicates.

  I was looking into IIS log files and I noticed that user opened the web page but he was inactive for more than a hour and then submits the form. I suspect, this form submission created duplicate records in DB because after this step, User was getting Invalid exception indicating duplicates.

  I can see more than one post request was created within same span of time but I am not sure whether user has clicked the Save action multiple times. But when tried this steps from my end there are no duplicates created.

  I would appreciate any leads to simulate the problem and appropriate solution for this issue.
• CheckBox Value dosent show up When Modelstate is not valid on RegisterForm

  i have a signup view with checkBoxOption

   <div class="form-group">
                  @Html.Label("Whice Console You Play?")
                  @for (int i = 0; i < Model.ConsolesCheckBoxList.Count; i++)
                       {
  
                        @Html.CheckBoxFor(m => Model.ConsolesCheckBoxList[i].IsChecked)
                        @Html.HiddenFor(m => Model.ConsolesCheckBoxList[i].ConsoleId)
                        @Html.DisplayFor(m => Model.ConsolesCheckBoxList[i].ConsoleName)
  
  
                      }
              </div>
  

  when one of the input in this form not good or not been insert, there are the ValidationMessageFor and the view is redisplay, after that the value of the checkbox are been gone, why that?

  this is the code for controller:

  [HttpPost]
      [AllowAnonymous]
      [ValidateAntiForgeryToken]
      public async Task<ActionResult> Register([Bind(Exclude = "UserPhoto")]CommenModel model)
      {
          if (ModelState.IsValid)
          {
              // To convert the user uploaded Photo as Byte Array before save to DB
              byte[] imageData = null;
              if (Request.Files.Count > 0)
              {
                  HttpPostedFileBase poImgFile = Request.Files["UserPhoto"];
  
                  using (var binary = new BinaryReader(poImgFile.InputStream))
                  {
                      imageData = binary.ReadBytes(poImgFile.ContentLength);
                  }
              }
  
  
  
  
              var user = new ApplicationUser
              {
                  UserName = model.registerViewModel.Email,
                  Email = model.registerViewModel.Email,
                  Phone = model.registerViewModel.Phone
  
              };
  
  
  
              user.UserPhoto = imageData;
              var result = await UserManager.CreateAsync(user, model.registerViewModel.Password);
  
              //after the user create, we will use the id and add the id to the userAddress table include
              // Address, langitud and latitude.
              using (ApplicationDbContext dbo = new ApplicationDbContext())
              {
                  var currentUserId = user.Id;
                  var pasinfo = dbo.userAddress.FirstOrDefault(d => d.Userid == currentUserId);
  
                  if (pasinfo == null)
                  {
                      pasinfo = dbo.userAddress.Create();
                      pasinfo.Userid = currentUserId;
                      dbo.userAddress.Add(pasinfo);
                  }
                  pasinfo.Address = model.useraddress.Address;
                  pasinfo.latitude = model.useraddress.latitude;
                  pasinfo.longitude = model.useraddress.longitude;
                  dbo.SaveChanges();
  
                  // now we used foreach loop to check which box is set to true on the view, and if the box set to true
                  // we take the id of the boxname and save it in conoleid.
                  foreach (var item in model.ConsolesCheckBoxList.Where(x => x.IsChecked).Select(x => x.ConsoleId))
                  {
                      var consoleid = item;
                      //here we create a new consoleuserInfo to insert data.
                      var consoleUserInfo = new ConsoleUserInfo
                      {
                          //we insert the id of user, and the consoleid of the checkbox how been marked.
                          Userid = currentUserId,
                          ConsoleId = consoleid
  
  
                      };
                      dbo.consoleUserInfo.Add(consoleUserInfo);
  
  
                  }
                  dbo.SaveChanges();
  
              }
  
  
              if (result.Succeeded)
              {
  
                  // await SignInManager.SignInAsync(user, isPersistent: false, rememberBrowser: false);
  
  
                  // Send an email with this link
                   string code = await UserManager.GenerateEmailConfirmationTokenAsync(user.Id);
                   var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: Request.Url.Scheme);
                   await UserManager.SendEmailAsync(user.Id, "Confirm your account", "Please confirm your account by clicking <a href=\"" + callbackUrl + "\">here</a>");
  
                  return RedirectToAction("Index", "Home");
  
              }
              AddErrors(result);
          }
  
          // If we got this far, something failed, redisplay form
          return View(model);
      }
  

  and this is my get view on my controller:

   // GET: /Account/Register
      [AllowAnonymous]
      public ActionResult Register()
  
      {
          //using database
          using (ApplicationDbContext dbo = new ApplicationDbContext())
          {
              //data will save list of the consoleCheckBoxItem
              var data = dbo.consolesCheckBox.ToList();
              // because the view is request a common model, we will create new one
              CommenModel a = new CommenModel();
              a.ConsolesCheckBoxList = data;
              //  we will need to return common model, that way we will returen a
  
  
              return View(a);
  
          }
      }