Question

I am using MVC-Viewmodel EF Model First, I am trying to make 2 forms in my View, one for CREATE and the other one for DELETE.
But I cant get it to work… I get this error:

 There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'Sname'.

I think this happens beacuse I have this code in my DeleteSubjectType for the dropdownlist and its suppose to be there since im using 2 forms. Somehow the action DeleteSubjectType aint working in my form.

I would appreciate if someone could take a look at my code:

This is my controller with my actions that I want to use in my view beginforms:

public ActionResult CreateSubjectType()
{
    CreateViewModel model = new CreateViewModel();
    return View(model);
}
[HttpPost]
public ActionResult CreateSubjectType(CreateViewModel model)
{
    if (ModelState.IsValid)
    {
        SubjectType s = new SubjectType();
        s.Sname = model.Sname2;                            
        Arep.addsubject(s);
        Arep.save();
        return RedirectToAction("CreateSubjectType");
    }
    return View(model);
}


public ActionResult DeleteSubjectType(int id)
{
    CreateViewModel model = new CreateViewModel();
    List<SubjectType> subjectypes = Arep.getallS();
    model.SubjectTypes = new SelectList(subjectypes, "SID", "Sname");

    SubjectType SubjectTypeToDelete = Arep.getbysid(id);
    return View(model);
}

[HttpPost]
public ActionResult DeleteConfirmed2(int id)
{
    SubjectType SubjectTypeToDelete = Arep.getbysid(id);
    Arep.DeletSubjects(SubjectTypeToDelete);
    Arep.save();
    return RedirectToAction("Index");

}

This is my view:

@model NKI3.ViewModels.CreateViewModel
@using (Html.BeginForm("CreateSubjectType","Admin",FormMethod.Post))
{

    @Html.ValidationSummary(true)
        <fieldset>
        <legend>Skapa ny utvärderingsobjekt</legend>
        <div class="editor-label">
        @Html.LabelFor(model => model.Sname2, "Välj ny utvärderingsobjekt")
        </div>
        <div class="editor-field">
        @Html.EditorFor(model => model.Sname2)
        @Html.ValidationMessageFor(model => model.Sname2)
        </div>
        <p>
        <input type="submit" value="Lägg till" />
        </p>
        </fieldset>

    }  
         @using (Html.BeginForm("DeleteSubjectType","Admin",FormMethod.Post))
         {   

            <fieldset>  
            <legend>Ta bort utvärderingsobjekt</legend>
            <div class="editor-label">
            @Html.LabelFor(model => model.Sname, "Befintliga Utvärderingsobjekt")
            </div>
            <div class="editor-field">
            @Html.DropDownListFor(f => f.Sname, Model.SubjectTypes)
            @Html.ValidationMessageFor(model => model.Sname)
            </div>
            <p>
            <input type="submit" value="Ta bort" />
            </p>    
            </fieldset>
         }

    <div>
        @Html.ActionLink("Tillbaka", "Index")
    </div>

Thanks in advance!

Answer 1

From your question it is not clear to which of the two GET actions that you have shown is this view associated: is it the CreateSubjectType action or the DeleteSubjectType action? Or even maybe some other action which you haven’t shown?

If we consider that it is the CreateSubjectType.cshtml then you have a problem because in this view you are attempting to create a dropdownlist in the delete form for the Sname property. Except that in your CreateSubjectType you never initialized the SubjectTypes property of your view model to a SelectList as you did in the DeleteSubjectType action.

So make sure that you properly initialize this property:

public ActionResult CreateSubjectType()
{
    CreateViewModel model = new CreateViewModel();
    List<SubjectType> subjectypes = Arep.getallS();
    model.SubjectTypes = new SelectList(subjectypes, "SID", "Sname");
    return View(model);
}

Also your delete form seems to be posting to the DeleteSubjectType action:

@using (Html.BeginForm("DeleteSubjectType","Admin",FormMethod.Post))

except that on your controller I see:

[HttpPost]
public ActionResult DeleteConfirmed2(int id)

instead of:

[HttpPost]
public ActionResult DeleteSubjectType(int id)

which I guess you were forced to do to avoid the overload resolution conflict you had with the GET action with the same name. In this case you could do this:

[HttpPost]
public ActionResult DeleteSubjectType(int id, FormCollection fc)