private void Kitaplar_Load(object sender, EventArgs e) { LoadBooks(); List <AuthorModel> authors = AuthorHelper.MapAuthorEntity(AuthorHelper.ListAuthors()); listBox1.DataSource = authors; listBox1.SelectionMode = SelectionMode.MultiSimple; List <GenreModel> genres = GenreHelper.MapGenreEntity(GenreHelper.ListGenres()); listBox2.DataSource = genres; listBox2.SelectionMode = SelectionMode.MultiSimple; }