Problem with GroupBox when calling member event vb.net 2005

I have this class:

Public Class common
Public Function NumbersOnlyEvent(ByVal CtrlName As String, ByVal type As String, ByVal formName As Object) As String

    Dim ctrlType As String = "System.Windows.Forms." & type

    For Each objcontrol As Control In formName.Controls

        If objcontrol.GetType.ToString = ctrlType And objcontrol.Name.Contains(CtrlName) Then

            AddHandler objcontrol.KeyPress, AddressOf Number开发者_如何学编程sOnlyHandler

        End If

    Next

    Return True

End Function 'NumbersOnlyEvent

Private Sub NumbersOnlyHandler(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs)

    If Char.IsDigit(e.KeyChar) Or e.KeyChar = Chr(8) Then
        e.Handled = False
    Else
        e.Handled = True
    End If

End Sub
 End Class

And i have this Form Class:

Public Class addbet
Dim CommonFunc As common = New common

Private Sub addbet_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    'AddHandler Events
    CommonFunc.NumbersOnlyEvent("txtSbcNum", "TextBox", Me)
End Sub
End Class

And i have this textboxes:

txtSbcNum1
txtSbcNum2
.
.
.
txtSbcNum15

When I add an eventhandler by calling CommonFunc.NumbersOnlyEvent("txtSbcNum", "TextBox", Me) on Form_Load, it works fine. But when I place my textboxes on a GroupBox, it doesn't work but when I remove it again to GroupBox it works again. Did i missed something?

The problem is that the form controls don't include child controls. So, the group box is found on the form but not the text box, since it is a child of the group box.

Change this line:

CommonFunc.NumbersOnlyEvent("txtSbcNum", "TextBox", Me)

to this:

CommonFunc.NumbersOnlyEvent("txtSbcNum", "TextBox", Me.GroupBox1)

so that it will find the text box in the group box.