Trey Carroll Trey Carroll - 1 month ago 10
C# Question

MVC3 DropDownListFor - a simple example?

I'm having trouble with

DropDownListFor
in my MVC3 app. I was able to use StackOverflow to figure out how to get them to appear on the View, but now I don't know how to capture the values in its corresponding properties on the View Model when it's submitted. In order to get this to work I had to create an inner class that had an ID and a value property, then I had to use an
IEnumerable<Contrib>
to satisfy the
DropDownListFor
parameter requirements. Now, however, how is MVC FW supposed to map the value that is selected on this drop-down back into the simple string property on my view model?

public class MyViewModelClass
{
public class Contrib
{
public int ContribId { get; set; }
public string Value { get; set; }
}

public IEnumerable<Contrib> ContribTypeOptions =
new List<Contrib>
{
new Contrib {ContribId = 0, Value = "Payroll Deduction"},
new Contrib {ContribId = 1, Value = "Bill Me"}
};

[DisplayName("Contribution Type")]
public string ContribType { get; set; }
}


In my View I place the dropdown on the page like this:

<div class="editor-label">
@Html.LabelFor(m => m.ContribType)
</div>
<div class="editor-field">
@Html.DropDownListFor(m => m.ContribTypeOptions.First().ContribId,
new SelectList(Model.ContribTypeOptions, "ContribId", "Value"))
</div>


When I submit the form the
ContribType
is (of course) null.

What is the correct way to do this?

Answer

You should do like this:

@Html.DropDownListFor(m => m.ContribType, 
                new SelectList(Model.ContribTypeOptions, 
                               "ContribId", "Value")

Where:

m => m.ContribType

is a property where the result value will be.