DropDownList not working

Hello!

Im trying to populate a dropdownlist with a list of value that sometimes may come in with a selected value. My problem is that it gives me this error:

The ViewData item that has the key 'ModuleID' is of type 'System.Guid' but must be of type 'IEnumerable<SelectListItem>'.

This is my view:

@Html.LabelFor(model => model.ModuleID, "Module")

</div>

@Html.DropDownList("ModuleID", "Please select")

@Html.ValidationMessageFor(model => model.ModuleID)

</div>

This is my Controller with the Action and method to populate the list:

void PopulateModuleList(Guid selectedModule)

{

List<Module> modules = SecurityModuleViewModelBuilder.ConvertToModules(repository.GetModules(true));

Module module = modules.Find(m => m.ID == selectedModule);

ViewBag.ModuleID = new SelectList(modules, "ID", "Name", module);

}

public ActionResult CreateTask(Guid? id)

{

Task task = new Task();

if (id.HasValue && id.Value != Guid.Empty)

PopulateModuleList(id.Value);

return View(task);

}

The behaviour Im looking for is that when an GUID is past that value comes in as selected on the view and when it is not, display Please select.

Thanks!

Re: DropDownList not working

humble-apprentice
The ViewData item that has the key 'ModuleID' is of type 'System.Guid' but must be of type 'IEnumerable<SelectListItem>'.

Where do you populate with System.Guid ? please show all code!

Re: DropDownList not working

ModuleID is a property of Task of type Guid.

This is how I solved the issue:

void PopulateModuleList(Guid selectedModule)
        {
            List<Module> modules = SecurityModuleViewModelBuilder.ConvertToModules(repository.GetModules(true));

            if (selectedModule != Guid.Empty)
                ViewBag.ModuleID = new SelectList(modules, "ID", "Name", selectedModule);
            else
                ViewBag.ModuleID = new SelectList(modules, "ID", "Name");
        }

        public ActionResult CreateTask(Guid? id)
        {
            Task task = new Task();

            if (id.HasValue && id.Value != Guid.Empty)
                PopulateModuleList(id.Value);
            else
                PopulateModuleList(Guid.Empty);

            return View(task);
        }

This code populates the dropdown, if an ID is passed it is set as selected and if not it just displays the list.