// добавление\удаление в историю public SearchMangaType Toggle(ref ObservableCollection <InHistory> History) { switch (_is_added) { case SearchMangaType.ALREADY_ADDED: break; case SearchMangaType.NOT_ADDED: History.Insert(0, new InHistory(Manga)); _is_added = SearchMangaType.NOW_ADDED; break; case SearchMangaType.NOW_ADDED: History.Remove(History.Single(InHistory => Manga.Compare(InHistory.Manga))); _is_added = SearchMangaType.NOT_ADDED; break; default: break; } RaiseProperty("is_added"); return(_is_added); }