How do I validate multiple radio buttons in a ASP.NET repeater in C#

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I have multiple radio buttons and I'm using a group name to choose at least 1 of the 2 options. I can't seem to get the GroupName so I can validate them with a submit button is clicked.

Thanks for any help

What I have tried:

<asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="* Select an option" ForeColor="#ff0000" OnServerValidate="option1_Validation" Display="Dynamic" /> 

<myRepeater>

<asp:RadioButton ID="rdOption1" Text="Option_1" GroupName="gnOption1" runat="server" />

<asp:RadioButton ID="rdOption2" Text="Option_2" GroupName="gnOption1" runat="server" />

</myRepeater>

 protected void option1_Validation(object source, ServerValidateEventArgs args)
    {
        bool itemSelected = false;
        foreach (RepeaterItem ri in myRepeater.Items)
        {
            RadioButton rb= (RadioButton)ri.FindControl("gnOption1");
            {               
              if (rb.GroupName == "gnOption1" && rb.Checked == true)
                {
                    itemSelected = true;

                }
                args.IsValid = itemSelected;
            }
        }
    }

Posted 22-May-18 8:10am

Commish13

Updated 22-May-18 9:33am

v2

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Comments

Richard Deeming 22-May-18 15:33pm

ri.FindControl("gnOption1")

No, your control's ID is not "gnOption1" either.

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Richard Deeming · Answer 1 · 2018-05-22T09:07:00

Quote:

RadioButton rb= (RadioButton)ri.FindControl("Game_1");

The FindControl method[^] expects a parameter representing the ID of the control you want to find.

You do not have a control with the ID Game_1 inside your repeater, so FindControl will return null, and you will get a NullReferenceException.

You need to pass in the correct ID for the control you're trying to find:

C#

bool itemSelected = false;
foreach (RepeaterItem ri in myRepeater.Items)
{
    RadioButton rb = (RadioButton)ri.FindControl("rdOption1");
    if (rb.Checked) 
    {
        itemSelected = true;
        break;
    }
}

args.IsValid = itemSelected;

NB: This will validate whether "Option_1" is selected in any item. If that's not what you're trying to validate, then you'll need to explain your requirement.

EDIT: If you want to validate that one of the radiobuttons is selected in each item:

C#

args.IsValid = true;

foreach (RepeaterItem ri in myRepeater.Items)
{
    RadioButton rb = (RadioButton)ri.FindControl("rdOption1");
    if (rb.Checked) continue;
    
    rb = (RadioButton)ri.FindControl("rdOption2");
    if (rb.Checked) continue;
    
    // Neither option is selected:
    args.IsValid = false;
    break;
}