private void doRemoveSlides(List <SlideInfo> removedSlides) { bool wasAllowingUndo = allowUndoCreation; allowUndoCreation = false; foreach (SlideInfo slideInfo in removedSlides) { slideshow.removeSlide(slideInfo.Slide); if (SlideRemoved != null) { SlideRemoved.Invoke(slideInfo.Slide); } } allowUndoCreation = wasAllowingUndo; }