Sub ControlInit(ByVal MyForm As Form)
 
        For Each ParentControl As Control In MyForm.Controls()
            Select Case LCase(ParentControl.GetType.Name)
                Case "textbox", "combobox"
                    AddHandler ParentControl.KeyDown, AddressOf AllesMarkieren
            End Select
            If ParentControl.HasChildren Then SubControls(ParentControl)
        Next
 
    End Sub
 
    Sub SubControls(ByVal ParentControl As Control)
 
        For Each SubControl As Control In ParentControl.Controls
            Select Case LCase(SubControl.GetType.Name)
                Case "textbox", "combobox"
                    AddHandler SubControl.KeyDown, AddressOf AllesMarkieren
            End Select
            If SubControl.HasChildren Then SubControls(SubControl)
        Next
 
    End Sub
 
    Sub AllesMarkieren(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.KeyEventArgs)
 
        If e.Control Then
            Select Case e.KeyCode
                Case Keys.A
                    sender.selectall()
            End Select
        End If
 
    End Sub