Asp.net MVC, Html.DropDownList and Selected Value

3/9/2009 12:14:59 AM #

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!

Martin Evans

3/11/2009 8:28:05 AM #

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

http://

4/5/2009 4:03:57 PM #

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();
            try
            {
                img.Description = Description;
                img.Rating = Rating;
                
                img.CategoryReference.EntityKey = new System.Data.EntityKey("StudiomorphEntities.CategorySet",
                   "CategoryId", new Guid(CategoryId));
.......
db.SaveChanges();

HeartattacK

4/7/2009 2:43:13 AM #

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 -
<% =Html.DropDownList("PropertyStyleId", (SelectList)ViewData["PropertyStyles"], "(Select Style)")%>

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

Matt

4/15/2009 1:57:51 AM #

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

www.almny.com

4/22/2009 1:45:42 PM #

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

HTML:

                Difficulty:
                <% =Html.DropDownList("DifficultyID")%>
                <%= Html.ValidationMessage("DifficultyID", "*") %>

                Category:
                <%=Html.DropDownList("CategoryID")%>
                <%= Html.ValidationMessage("CategoryID", "*") %>
            

4/23/2009 8:34:46 AM #

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.

http://

4/23/2009 8:59:37 PM #

Shailja, this is about MVC, not webforms.

HeartattacK

5/10/2009 4:13:16 AM #

thanks for your reply

www.almny.com

9/9/2009 1:07:11 AM #

I am using 'SelectList' within in dropdown as below by sepcifying

1. Country object collection 2.valuefield 3.textfield 4.selectedValue (country object) which are exposed as properties in my View Model Object.Controller is filling up this properties after post back happens.But last value - 'selectedValue' is not working as expected.Controller is setting previosuly selected country to this property after post back but it is not binding to dropdown control after postabck.As result always first item of drop down is being selected by default.So why attribute 'selectedValue' not working ? Any idea/solution ?

<%= Html.DropDownList("Countries", new SelectList (Model.Countries,"Id","Name",Model.SelectedCountry))%>

Deepak