The ViewData item that has the key 'GenderID' is of type 'System.Int32' but must be of type 'IEnumerable<SelectListItem>'

Question

The error occurs when i tried to Submit/Post the data... could someone please help i tried every post but they are not helping me. I am new to mvc... any help will be granted here is my code...

public ActionResult Create()
{
   UserProfileCreateViewModel model = new UserProfileCreateViewModel();
   model.Gender = _GenderRepository.GetAll()
       .Select(x => new SelectListItem
       {
           Value = x.ID.ToString(),
           Text = x.DESCRIPTION
       });
   return View(model);
}

[HttpPost]
public ActionResult Create(UserProfileCreateViewModel model)
{
   if (ModelState.IsValid)
   {
      UserProfile user = new UserProfile();
      user.GENDER_ID = model.GenderID;
      _UserProfileRepository.Add(user);
      _UserProfileRepository.Save();
      return RedirectToAction("Index", "Home");
   }
   return View(model);
}

View

<div class="form-group">
   @Html.LabelFor(model => model.GenderID, new { @class = "control-label col-md-2" })
   <div class="col-md-10">
      @Html.DropDownListFor(model => model.GenderID, Model.Gender, "Select from List", new { @class = "form-control" })
      @Html.ValidationMessageFor(model => model.GenderID, string.Empty, new { @class = "text-danger" })
   </div>
</div>

Model

public class UserProfileCreateViewModel
{
   [Required(ErrorMessage="{0} is required")]
    [Display(Name="Gender")]
    public int GenderID { get; set; }
    public IEnumerable<SelectListItem> Gender { get; set; }
}

InvalidOperationException: The ViewData item that has the key 'GenderID' is of type 'System.Int32' but must be of type 'IEnumerable<SelectListItem>'.

Here i have tried this.... // POST: /UserProfile/Create/

 [HttpPost]
    public ActionResult Create(UserProfileCreateViewModel model)
    {
        if (ModelState.IsValid)
        {
            UserProfile user = new UserProfile();

            user.GENDER_ID = model.GenderID;

            _UserProfileRepository.Add(user);
            _UserProfileRepository.Save();

            return RedirectToAction("Index", "Home");
        }
        model.Gender = _GenderRepository.GetAll().Select(x =>
                                                    new SelectListItem
                                                    {
                                                        Value = x.ID.ToString(),
                                                        Text = x.DESCRIPTION
                                                    });
        return View(model);
    }

Add your stacktrace or at least point out where the exception is being raised. — Chris Pratt
Exception is raised at View At this line @Html.DropDownListFor(model => model.GenderID, Model.Gender, "Select from List", new { @class = "form-control" }) — Secret Star
I'm pretty sure you're passing the wrong parameters to the DropDownListFor function. I think you should be creating a new SelectList somewhere in there... — Timothée Bourguignon
I have created the dropdownlist in the same way in another project its working fine there but not working here. — Secret Star

Unknown Unknown · Accepted Answer · 2015-12-15T20:09:58

The error means that the value of Model.Gender is null (and as a result the DropDownListFor() method expects that the first parameter is IEnumerable<SelectListItem>.

In your case, when you submit the form and ModelState is invalid, you return the view and have not assigned a value to Model.Gender (hence it is null and the excption is thrown.

Ensure that you re-assign the value of Model.Gender in the POST method (just as you did in the GET method) before you return the view.

The ViewData item that has the key 'GenderID' is of type 'System.Int32' but must be of type 'IEnumerable<SelectListItem>'

2 Answers