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

You should take some look at the CheckedChanged event to register the corresponding event handler and store the Checked radio button state in some variable. However, I would like to use LINQ here just because you have just some RadioButtons which makes the cost of looping acceptable:

var checkedRadio = new []{groupBox1, groupBox2}
                   .SelectMany(g=>g.Controls.OfType()
                                            .Where(r=>r.Checked))
// Print name
foreach(var c in checkedRadio)
   System.Diagnostics.Debug.Print(c.Name);