MVC4 - Setting Initially Selected Item in DropDownList

Question

I am passing in a list of objects to my View via a model

@model MyModel.ObjectViewModel

I am new to MVC and am trying to set the initially selected item of a dropdownlist in my view (modelled after an Edit).

I am then binding this to a drop down list as follows

<label for="ddlObjects">Select Object</label>
@Html.DropDownList("ddlObjects", Model.AllObjectsSelectList, Model.Object.ObjectName)

The above does make the drop down list have the correct object selected initially, but I discovered it is only in the form of text. The real object isn't chosen and as such the value isn't used. How can I have a list of items, say, "Object1" "Object2", etc and have the default be a specific one?

When I'm passing through the item I only know the text value (the name that appears in the drop down list) of the item, I don't know it's inner value so I can't really use SelectListItem {Text = "X", Value= "Y"}

I have searched here and through google, and there are options for setting the intially selected value, however they are using methods like @Html.DropDownList for which doesn't seem to let me specify a control name, and in my controller I specifically reference the name of the control.

forums.asp.net/t/1761365.aspx/1 OR stackoverflow.com/questions/16298346/… — Suraj Singh
That kind of works in that it says it should set the default to X but it doesn't seem to change it when I actually run the app and go to the page. (second link). — MattR
Why not use Viewbag or ViewData to carry your selected id(value) to view and assign that value to selected value overload for dropdown , So your selected id(value) could be dynamic. — Suraj Singh
Because I don't have the ID, I only have the text value. I'm dealing with data I get from SQL and instead of storing the ID and using Joins to normalise the table it is just passing the string name of the object. — MattR
Try to pass your TextField and Valuefield both as the name Something like this SelectListItem {Text = "X", Value= "X"} . — Suraj Singh

MattR MattR · Accepted Answer · 2013-08-15T10:03:05

My work around wasn't pretty, but it could be easily refactored to be much nicer. It will just be a case of some effort which at present I don't have time for - but I will in the next week or so.

I created a method in my controller which I pass in my list of items (selectList, which you would think would work anyway... but it doesn't) then I work out which is the object I require and set the Selected property to true.

private List<SelectListItem> GetListOfObjectTypes(SelectList selectList, string objectTypeName, string objectTypeId)
{
    List<SelectListItem> items = new List<SelectListItem>();
    foreach (METAObjectType item in selectList.Items)
    {
         bool isSelected = false;
         if (item.Name == objectTypeName)
         {
                isSelected = true;
         }
         items.Add(new SelectListItem {Selected= isSelected, Text=item.Name, Value=item.ObjectTypeId.ToString()});
        }
        return items;
    }

I then just pass this through to my View and set it as the list in the @Html.DropDownList and it will now select the correct item by default.

MVC4 - Setting Initially Selected Item in DropDownList

1 Answers