How do I get which radio button is checked from a groupbox?

Question

I have these groupboxes:

I want to run some code according to checked

Answer 1

Rather than checking all RadioButtons, use the Validated event of the GroupBox.

private void grpBox_Validated(object sender, EventArgs e)
    {
        GroupBox g = sender as GroupBox;
        var a = from RadioButton r in g.Controls where r.Checked == true select r.Name;
        strchecked = a.First();
     }