How to find checked RadioButton inside Repeater Item? - asp.net

Question

I have a Repeater control on ASPX-page defined like this:
<asp:Repeater ID="answerVariantRepeater" runat="server"
onitemdatabound="answerVariantRepeater_ItemDataBound">
<ItemTemplate>
<asp:RadioButton ID="answerVariantRadioButton" runat="server"
GroupName="answerVariants"
Text='<%# DataBinder.Eval(Container.DataItem, "Text")%>'"/>
</ItemTemplate>
</asp:Repeater>
To allow select only one radio button in time I have used a trick form this article.
But now when form is submitted I want to determine which radio button is checked.
I could do this:
RadioButton checkedButton = null;
foreach (RepeaterItem item in answerVariantRepeater.Items)
{
RadioButton control=(RadioButton)item.FindControl("answerVariantRadioButton");
if (control.Checked)
{
checkedButton = control;
break;
}
}
but hope it could be done somehow simplier (maybe via LINQ to objects).

Answer 1

You could always use Request.Form to get the submitted radio button:
var value = Request.Form["answerVariants"];
I think the submitted value defaults to the id of the <asp:RadioButton /> that was selected, but you can always add a value attribute - even though it's not officially an <asp:RadioButton /> property - and this will then be the submitted value:
<asp:RadioButton ID="answerVariantRadioButton" runat="server"
GroupName="answerVariants"
Text='<%# DataBinder.Eval(Container.DataItem, "Text")%>'"
value='<%# DataBinder.Eval(Container.DataItem, "SomethingToUseAsTheValue")%>' />

Answer 2

Since You are using javascript already to handle the radio button click event on the client, you could update a hidden field with the selected value at the same time.
Your server code would then just access the selected value from the hidden field.

Answer 3

I'm pretty sure that the only thing you could use LINQ to Objects for here would be to take the conditions from within the foreach loop and move them to a where clause.
RadioButton checked =
(from item in answerVariantRepeater.Items
let radioButton = (RadioButton)item.FindControl("answerVariantRadioButton")
where radioButton.Checked
select radioButton).FirstOrDefault();