private void addBookButton_Click(object sender, EventArgs e) { var addBookForm = new AddBookForm(); DialogResult dialogResult = addBookForm.ShowDialog(this); if (dialogResult == DialogResult.Cancel) { return; } string name = addBookForm.nameTextBox.Text; string editor = addBookForm.editorTextBox.Text; string type = addBookForm.typeTextBox.Text; string genre = addBookForm.genreTextBox.Text; string language = addBookForm.languageTextBox.Text; var editionYear = new DateTime((int)addBookForm.editionNumericUpDown.Value, 1, 1); BookRepository bookRepository = new BookRepository(); var book = new Book { Name = name, EditorsName = editor, EditionYear = editionYear, Type = type, Genre = genre, Language = language }; bookRepository.Create(book); int id = 0; var bookAuthorRepository = new BookAuthorRepository(); BookAuthor bookAuthor; foreach (object ch in addBookForm.authorsCheckedListBox.CheckedItems) { id = int.Parse(ch.ToString().Split(' ')[0]); bookAuthor = new BookAuthor { BookId = book.Id, AuthorId = id }; bookAuthorRepository.Create(bookAuthor); } int booksCount = (int)addBookForm.countNumericUpDown.Value; var bookCopyRepository = new BookCopyRepository(); BookCopy bookCopy; for (int i = 0; i < booksCount; i++) { bookCopy = new BookCopy { BookId = book.Id, CopyNumber = i + 1 }; bookCopyRepository.Create(bookCopy); } SetDataGridView(); _db.SaveChanges(); }