DropdownList's selectedValue doesn't get affected with value from DB

This problem has been driving me crazy and Monday mornings don't really help.

I'm loading 2 dropdownboxes like so:

• This one gets its selectedvalue affected by the db value

  <dd><%= Html.DropDownList("type", New SelectList(ViewData("typeList"), 
      "value", "text", Model.type), New With {.class = ""})%></dd>
  

• This one ignores the value loaded in the model and always displays the first value in the dropdownbox

  <dd><%= Html.DropDownList("action", New SelectList(ViewData("actionList"), 
      "value", "text", Model.action), New With {.class = ""})%></dd>    
  

I've already debugged this page and Model.Action comes loaded with the correct values but they never get assigned to the selectedvalue.

EDIT:

This is the ActionResult which displays the page:

<Authorize()> _
        Public Function Edit(ByVal id As Guid) As ActionResult
            Dim article As Article_Ad = articleAdRepository.GetById(id)

            ViewData("actionList") = GetActionValues()
            ViewData("typeList") = GetTypeValues()

            Return View(article)
        End Function

And these are the functions which feed the dropdownboxes:

Private Function GetTypeValues() As IEnumerable(Of SelectListItem)
            Dim list As New List(Of SelectListItem)
            Dim sel As SelectListItem

            'Imagem
            sel = New SelectListItem
            sel.Text = "Imagem"
            sel.Value = "image"
            list.Add(sel)

            'Video
            sel = New SelectListItem
            sel.Text = "Video"
            sel.Value = "video"
            list.Add(sel)

            Return list
        End Function

        Private Function GetActionValues() As IEnumerable(Of SelectListItem)
            Dim list As New List(Of SelectListItem)
            Dim sel As SelectListItem

            ' Call browser window
            sel = New SelectListItem
            sel.Text = "Mostrar Janela"
            sel.Value = 1
            list.Add(sel)

            ' Play fullscreen video
            sel = New SelectListItem
            sel.Text = "Mostrar Video em FullScre开发者_如何学Pythonen"
            sel.Value = 2
            list.Add(sel)

            ' Show fullscreen picture
            sel = New SelectListItem
            sel.Text = "Mostrar Imagem em FullScreen"
            sel.Value = 3
            list.Add(sel)

            Return list
        End Function

Could you try setting the correct SelectListItem.Selected value? I am assuming the Imagem item is supposed to be selected below.

Private Function GetTypeValues() As IEnumerable(Of SelectListItem)
    Dim list As New List(Of SelectListItem)
    Dim sel As SelectListItem

    'Imagem
    sel = New SelectListItem
    sel.Text = "Imagem"
    sel.Value = "image"
    sel.Selected = True ' This line has been added
    list.Add(sel)
    '...

    Return list
End Function

I've taken a similar approach to you where I build out the SelectList in my viewmodel and reference it from my views with Html.DropDownList.

One big difference is that I always set my value/text parameters to string values even if the corresponding data is int.

Example (C# - sorry):

private List<SelectListItem> widgets;

public List<SelectListItem> Widgets
{
  get
  {
    if (widgets == null)
    {
      widgets = new List<SelectListItem>();
      widgets.Add(new SelectListItem { Value = "10", Text = "10" });
      widgets.Add(new SelectListItem { Value = "25", Text = "25" });
      widgets.Add(new SelectListItem { Value = "50", Text = "50" });
      widgets.Add(new SelectListItem { Value = "100", Text = "100" });
      widgets.Add(new SelectListItem { Value = "500", Text = "500" });
    }
    return widgets;
  }
  private set { }
}

Another difference although I doubt it is responsible for this problem is that I strongly type my views to a view model and then I access the view model's SelectList property directly from the view vs. assigning it to viewdata in the controller. It looks like you bound your view directly to the entity (i.e. the domain model).

I found out the answer to this question and I feel slightly ashamed for the final result, to be honest. It seems that I was using the name "action" in a ViewData variable which made it conflict with the dropdownbox's name "action". After changing the ViewData to "actions" (added the "s") it stopped doing conflict and assigned the selectedvalue correctly.

My tip to anyone running into the same problem as me is to make sure there's no other control making use of the same name you are assigning to your object, just to be on the safe side.

Thanks to everyone for the pointers here.