private void FallReports_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) { if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add) { //add CurrentModel.AddFallReport(e.NewItems[0] as Report); PredictionAndRealFalls.AddReport((e.NewItems[0] as Report).location); } if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Remove) { //remove var oldId = (e.OldItems[0] as Report).id; CurrentModel.RemoveFallReport(oldId); } }