ASP.Net MVC view model for dropdownlist? - asp.net-mvc

Question

I am trying to work with a generated Month dropdownlist in MVC.
My viewmodel is:
public class MyViewModel{
public MyViewModel()
{
var monthNames = DateTimeFormatInfo.CurrentInfo.MonthNames.Take(12).ToList();
Months = new SelectList(monthNames.Select(m=> new{Id=monthNames.IndexOf(m)+1, Name=m}).ToList(),"Id","Name");
}
public IEnumerable<SelectListItem> Months{ get; set; }
public string Month{ get; set; }
}
My View is:
#Html.DropDownListFor(model=>model.Month, new SelectList(Model.Months))
The problem is that the Months property always returns a null value so the page errors when trying to render the DDL.
Seems pretty simple. What am I missing?

Answer 1

You're missing the part where you actually set the Months property to something other than null.
You should just define a custom getter on the property so it always returns an enumerable:
public IEnumerable<SelectListItem> Months
{
List<string> monthNames = DateTimeFormatInfo.CurrentInfo.MonthNames.Take(12).ToList();
foreach (var month in monthNames)
{
yield return new SelectListItem
{
Value = monthNames.IndexOf(month) + 1,
Text = month
};
}
}

Answer 2

As another possible solution using templates:
// in your model, decorate it to use the template
[UIHint("MonthName")]
public String Month { get; set; }
Then in ~/Views/Shared/EditorTemplates/MonthName.cshtml:
#model String
#Html.DropDown(
String.Empty,
#Model,
new SelectList(
System.Globalization.DateTimeFormatInfo.CurrentInfo.MonthNames
.Where(x => !String.IsNullOrEmpty(x))
.Select((x,y) => new { Text = x, Value = y + 1 }),
"Value",
"Text"
)
)
And finally, in your view:
#Html.EditorFor(x => x.Month)
though this is really only worth while on fixed-lists (like months), and not for things that may be dynamic based on the view being displayed.