Question

I have an HTML dropdown list:

<select name="status">  
       <option value="close" >Close Task</option>
       <option value="open" >Reopen Task</option>
  </select>

I want to set the ‘selected’ option based on the ‘Task.Completion’ property in my view model:

public class TaskEditViewModel
{
    public Task Task { get; set; }
    public TaskComment TaskComment { get; set; }
}

So if Task.Completion is NULL, the ‘close’ option is selected, otherwise the ‘open’ option is selected.

How can I do this?

Answer 1

Your view model doesn’t seem adapted to what you are trying to do in the view (which according to your question is show a dropdown list and preselect a value based on some property on your view model).

So a far more realistic view model would be this:

public class TaskEditViewModel
{
    public string Completion { get; set; }
    public IEnumerable<SelectListItem> Actions 
    { 
        get
        {
            return new[]
            {
                new SelectListItem { Value = "close", Text = "Close Task" },
                new SelectListItem { Value = "open", Text = "Reopen Task" },
            };
        }
    }
}

then you could have a controller action which will populate and pass this view model to the view:

public ActionResult Foo()
{
    var model = new TaskEditViewModel();

    // this will automatically preselect the second item in the list
    model.Completion = "open";

    return View(model);
}

and finally inside your strongly typed view you could use the DropDownListFor helper to render this dropdown:

@model TaskEditViewModel
@Html.DropDownListFor(x => x.Completion, Model.Actions)