private void UpdateBookmarks() { SelectedBook.BookMarks = _bookMarkService.GetAllForBook(SelectedBook); foreach (var bookmark in ShellViewModel.SelectedBook.BookMarks) { var page = PdfPages.GetPage(Convert.ToUInt32(bookmark.PageNumber)) as PdfPageViewModel; if (page != null) { page.BookMark = true; } } SelectedBook.BookMarks = SelectedBook.BookMarks.OrderBy(x => x.PageNumber).ToList(); }