private void ucField_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            var field = SelectedField;

            if (field != null)
            {
                FilterController = QueryFilterFactory.Create(field, SelectedFilterOperator);
                FilterOperatorViewSource?.View.Refresh();
            }
        }
        private void ConfigureFieldOperatorControl()
        {
            ucFilterOperator.BindToEnumUsingSource<FilterOperator>(FilterOperatorViewSource, FilterOperator.Eq);

            ucFilterOperator.SelectionChanged += (o, args) =>
            {
                FilterController = QueryFilterFactory.Create(SelectedField, SelectedFilterOperator);
            };
        }