private void Curves_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) { if (!hanldeCollectionChanges) { return; } removedCurves.Clear(); if (e.OldItems != null) { foreach (Curve curve in e.OldItems) { addedCurves.Remove(curve); } } if (e.NewItems != null) { foreach (Curve curve in e.NewItems) { addedCurves.Add(curve); } } mediaPlayer.ForseFrameRefreshOnPause(); }