Question

I’m working with C# + MVC3.
I have a radiobutton on a form, but I’m having some problems.

At Index.cshtml, I have:

<div class="display-label">
    Label
</div>
<div class="display-field">@Html.RadioButton("rdActive", ((FakeClass)ViewBag.FakeFilter).Situation, "S");

At Index of my Controller, i have:

    ViewBag.FakeFilter = new FakeClass()
    {
        Situacao = (Request.Form["rdActive"] == "" ? null : Request.Form["rdActive"])
    }

And I’m getting ArgumentNullPointerException

Answer 1

For what I understand of your error it’s throws Nullpontier because you’re receiving empty in the Request.Form["rdActive"] so when the code passes for the action returns null to the viewbag.

Now what i see strange it’s that the overload of the helper receives in the last parameters a Boolean and you’re passing an string with “s”.

this

@Html.RadioButton("rdActive", ((FakeClass)ViewBag.FakeFilter).Situation, "S")

Should be

@Html.RadioButton("rdActive", ((FakeClass)ViewBag.FakeFilter).Situation, true)

or

@Html.RadioButton("rdActive", ((FakeClass)ViewBag.FakeFilter).Situation, false)

Check the parameters