private void ControlSaveButtonState() { if (selectedPageRange != null) { if (SelectionOptions.SelectedIndex == 0) { // extract option if (selectedPageRange.IsEmpty()) { SaveButton.IsEnabled = false; } else { SaveButton.IsEnabled = true; } } else { // remove option if (selectedPageRange.IsEntire()) { SaveButton.IsEnabled = false; } else { SaveButton.IsEnabled = true; } } } }