How can I call a this Function that returns a RadioButtom name in a GroupBox

[Arve K.]

I think Inferrd got a point when he says that the Radiobuttons might actually not be where you think they are.

JMC have posted a nice snippet in this thread that iterates through every sub control. Based on that example, what happen if you change your function to this?

Private Function WhatRadioIsSelected(ByVal MainPanel As Panel) As String 'Note that it is iterating through the main panel controls and its child controls
    Dim result As String = Nothing
 
    Dim ctl As Control = MainPanel.GetNextControl(MainPanel, True) 'Get the first control in the tab order.
 
    Do Until ctl Is Nothing
        If TypeOf ctl Is GroupBox Then
            For Each ControlInGroupBox As Control In DirectCast(ctl, GroupBox).Controls.OfType(Of RadioButton)
                If DirectCast(ControlInGroupBox, RadioButton).Checked = True Then result = ControlInGroupBox.Text
            Next
        End If
 
        ctl = MainPanel.GetNextControl(ctl, True) 'Get the next control in the tab order.
    Loop
 
    Return result
End Function

Instead of using the groupbox as a parameter, use the main panel instead.

Messagebox.Show(WhatRadioIsSelected(pnlMainPanel))

Also I agree with Sytten, using a Usercontrol will result in a much lighter coding experience, and in my opinion adding and removing several controls and their event handlers in run time should only be used in special cases. I include a project related to your issue (which is slightly overkill for demonstrating purposes) where everything is designed in run time. The project only got a few controls, but image if there where tens or hundreds of them You can compare for yourself why the Usercontrol example is a good example