private void UpdateRegionFilter(FilterViewModel regions) { if (this.RegionMap == null || this.RegionMap.Series.Count == 0) { return; } var series = this.RegionMap.Series.OfType <GeographicShapeSeries>().Last(); series.ItemsSource = null; foreach (var shape in this.RegionsViewModel.SelectableShapeElements) { var region = regions.First(reg => reg.Name == shape.ShapeName); shape.IsSelected = region.IsSelected; } series.ItemsSource = this.RegionsViewModel.SelectableShapeElements; }