MVC3 SelectedValue

Question

In my model:

public SelectList QuestionGroupSelectList { get; set; }

------
List<QuestionGroup> questionGroupList = questionGroupRepository.GetQuestionGroup_BySurveyId(survey.Id);

Dictionary<int, string> questionGroupDictionary = questionGroupList.ToDictionary(l => l.Id, l => l.Name);

QuestionGroupSelectList = new SelectList(questionGroupDictionary, "key", "value", questionGroupId);





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In view:
@Html.DropDownList("QuestionGroupSelectList", Model.QuestionGroupSelectList, "Choose Here")

When i debug i get 2 items in QuestionGroupSelectList (one with Id 30 and one with Id 35), and it says that the selectedValue is 35 (questionGroupId = 35)

But the selectedvalue does not work in the view, any ideas?

Thanks in advance!

Answer 1

You should use a different property to bind your dropdownlist value to. Also you should use view models and strongly typed helpers, like this:

public class MyViewModel
{
    public int QuestionGroupId { get; set; }
    public SelectList QuestionGroupSelectList { get; set; }
}

then you could have a controller action which populates this view model and passes it to the view:

public ActionResult Foo()
{ 
    // This collection could come from anywhere 
    // normally you will query a repository here to fetch those values
    var values = new[] 
    {
        new { Key = "1", Value = "item 1" },
        new { Key = "2", Value = "item 2" },
        new { Key = "3", Value = "item 3" },
    }

    var model = new MyViewModel
    {
        // preselect the second value
        QuestionGroupId = 2,
        QuestionGroupSelectList = new SelectList(values, "Key", "Value")
    }
    return View(model);
}

and finally in your view:

@model MyViewModel

@Html.DropDownListFor(
    x => x.QuestionGroupId, 
    Model.QuestionGroupSelectList, 
    "Choose Here"
)