MVC 4: How to make DropDownListFor return 0 as optionLabel value?
asp.net-mvc, c#, razor
Solution
In the documentation for DropDownFor the `optionLabel` parameter (where you're passing "None") is described as:
The text for a default empty item.
So this is designed to always be an empty item. You will need to add an additional item into your select list in order to get a 0 value.
I have used the following extension method to accomplish this (sorry untested, there may be minor errors):
public IEnumerable<SelectListItem> InsertEmptyFirst(this IEnumerable<SelectListItem> list, string emptyText = "", string emptyValue = "")
{
return new [] { new SelectListItem { Text = emptyText, Value = emptyValue } }.Concat(list);
}
You would use it like this:
@Html.DropDownListFor(model => model.cardReward.ID, new SelectList(ViewBag.cardReward, "Id","Name").InsertEmptyFirst("None", "0"))
Problem
I have a create view with multiple DropDownListFors. Each time a new object is created only 1 of the DropDownListFors should have a value, I want the others to return 0 as the result when the optionLabel is left selected. How do I assign 0 as the value for a DropDownListFor's optionLabel? EDIT: Here is an example of my DropDownListFor code in my view: ``` @Html.DropDownListFor(model => model.cardReward.ID, new SelectList(ViewBag.cardReward, "Id","Name"), "None") ``` When I render the page it creates the list with None at the top like this: ``` <option value>None</option> ``` I want it to be like this: ``` <option value="0">None</option> ```