MVC, Html.DropDownList and Selected Value

I recently ran into the altogether common problem of the Html.DropDownList helper rendering a drop down list with no value selected. This is a major problem when editing data as by default, the first value is selected and saving would mean the first value is used.

There have been a few issues resulting in the same error. My issue was that I was setting the Name of the drop down list to be equal to the property on my model. I was using the Entity Framework, and had an Image class with a navigation property called Category. I was using this to render the ddl:

<%= Html.DropDownList("Category", (IEnumerable<SelectListItem>)ViewData["categories"])%>

In my controller, I was setting the ViewData like this:

this.ViewData["categories"] = new SelectList(db.CategorySet.ToList(), "CategoryId", "Title", img.CategoryReference.EntityKey);

Unfortunately, even though I had set the selected value (third parameter to the SelectList constructor), the ddl had no value selected.

The fix was quite simple:

<%= Html.DropDownList("CategoryId", (IEnumerable<SelectListItem>)ViewData["categories"])%>

I just changed the Name of the drop down and handled the assignment in the controller.

The reason behind this problem is that MVC first looks for a match between the name of the drop down and a property on the model. If there’s a match, the selected value of the SelectList is overridden. Changing the name of the drop down is all it takes to remedy the issue.


Hope that helps.


  • Thanks very much. This seems to be the only example any where on the internet where the viewdata is cast to IEnumerable in the markup!

  • Can you show the related code? i.e., CategorySet, CategoryReference, the controller method code?

  • Sorry for the delay in getting back to this..I was setting up my new apartment, and it took a LOT of work.

    The related code is very simple.

    img is an Image (not System.Drawing.Image, just an Entity).
    Each image has a Category. Each category can have one or mor Images.

    I'm using The Entity Framework, and CategorySet is the plural of Category.

    The controller to handle the postback is like this:
    public ActionResult Edit(string ImageId, string Description, int Rating, string CategoryId)
    Guid imageId = new Guid(ImageId);
    var img = db.ImageSet.Where(x => x.ImageId == imageId).First();
    img.Description = Description;
    img.Rating = Rating;

    img.CategoryReference.EntityKey = new System.Data.EntityKey("StudiomorphEntities.CategorySet",
    "CategoryId", new Guid(CategoryId));

  • I was experiencing a similar problem but I was eventually able to get the selected value to show without matching the name of the dropdown to a property of the select list.

    HTML -

    Controller Code -
    ViewData["PropertyStyles"] = new SelectList(_typeRepository.GetPropertyStyles(), "TypeId", "TypeDescription", t);

  • can i get the source code for how to bind dropdownlist from mvc

  • I have tried everything to get my Html.dropdownlist to work, but it's just not working.

    Controller code:

    Function Create() As ActionResult

    Dim allCats = chchtvdc.GetCategories
    ViewData("CategoryID") = New SelectList(allCats, "CategoryID", "CategoryName")

    Dim allDifficulties = chchtvdc.GetDifficulties
    ViewData("Difficulty") = New SelectList(allDifficulties, "DifficultyID", "DifficultyLevel")

    Return View()
    End Function




    I get the error:

    There is no ViewData item with the key 'DifficultyID' of type 'IEnumerable'.

    Any help will be appreciated.

  • This also works but the main reason of dropdownlist not showing the selected value is that the page is beingposted back whenever a button is clicked and thus the page_load event handler is called which in turn resets the selected value property , so to rectify just check in the page_load handler that wthr it is being posted back or being loaded for the first time , by inserting if page.ispostback = false.

  • Shailja, this is about MVC, not webforms.

  • thanks for your reply

  • Thanks.

    I discovered the same bug. Your fix worked.


  • Puta que pariu! Quero fórum em Português!! Não entendo nada que vcs falam!!!

  • There is one more method of selecting item described in this link to bind dropdownlist.

  • This issue was driving me nuts. I was tracing the SelectListItem enumeration and found that the item that I marked as selected was indeed kept selected but it was just not reflecting in the DropDownList. So, as you said, I changed the name of the DropDownList to match the property name on the model, and it worked fine. Thanks for the post. Much appreciated.

  • This really helped! Thanks!

  • Oi Brasileiro, se queresse em portugues, porque nao utilize o google translate?

  • Thanks for the post! It's helpful!

  • how to create dropdownlist

  • Worked great the first time. Saved me lots of time. Thanks!!!

  • Very helpful. Thanks

  • Fixed! thanks :)

  • Thanks you very much.

    I have a simple application for bind categories and it select the value of dropdownlist that, this is for selected product.

    I think this is very easy. no?

    in controller :

    public ActionResult Edit(int id)
    var p = db.ProductSet.First(a => a.ProductId == id);

    ViewData["categories"] = new SelectList(db.CategorySet.ToList(),
    "CategoryId", "CategoryName", p.Category.CategoryId);

    return View(p);

    and in view :

  • Thanks a lot!!! It really help me up, I had a while trying to figure out what was wrong in my code


    chk this for more information

  • I wonder whose brilliant idea it was to throw away the list you explicitly give it in favor of something it finds on the Model or ViewData.

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