why is my dropdown selection not being submitted? - asp.net-mvc

Question

I have a dropdown list when the form is submitted it is submitted null...
html:
#Html.DropDownListFor(c => Model.HowOftenCar, Model.HowOftenCar, new { id = "CompDrop" })
Model:
public IEnumerable<SelectListItem> HowOftenCar { get; set; }
Controller:
IList<string> HowOftenCar = new List<string>();
HowOftenCar.Insert(0, "More than once a week");
HowOftenCar.Insert(1, "Once a month");
HowOftenCar.Insert(2, "Once a year");
model.HowOftenCar = HowOftenCar.Select(c => new SelectListItem()
{
Text = c,
Value = c
});
Post:
[HttpPost]
public ActionResult Index(Competition model)
{
if (ModelState.IsValid)
{}
}
I have also tried...
#Html.DropDownListFor(c => Model.HowOftenCar, new SelectList(Model.HowOftenCar, "Value","Text"), new { id = "CompDrop" })

Answer 1

You're not using DropDownListFor correctly.
The first parameter is the property on the model you want to populate. If you want to populate the HowOftenCar property on the model, it should be of the type of the value - in this case, it looks like a string.
public string HowOftenCar { get; set; }
The second parameter is the list of choices. You've got that right, but it needs to be something else than the property you're trying to set.
IList<string> HowOftenCarChoices = new List<string>
{
"More than once a week",
"Once a month",
"Once a year"
};
model.HowOftenCarChoices = HowOftenCar.Select(c => new SelectListItem()
{
Text = c,
Value = c
});
So then you'll end up with
#Html.DropDownListFor(m => m.HowOftenCar, Model.HowOftenCarChoices)
Note that you don't need the id property, because DropDownListFor will automatically give it the id of HowOftenCar, based on the lambda.