private void ServiceOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs) { var item = sender as FieldForFilterDto; if (item != null) { if (FilterParentServiceList.Count(f => f.Selected) == 1) { ChangeParentService(FilterParentServiceList.FirstOrDefault(f => f.Selected)?.Id); } else { ChangeParentService(null); } } }