private void btnDone_Click(object sender, EventArgs e) { if (!IsValidTextBox()) { return; } DTO.SachDTO book = new DTO.SachDTO { Ma = GenerateBookId(), Ten = txtTitle.Text, MaTheLoai = cbCategory.SelectedValue.ToString(), MaTacGia = cbAuthor.SelectedValue.ToString(), MaMXB = cbPublisher.SelectedValue.ToString(), NgayXuatBan = dtpPublicationDate.Value, GiaTien = double.Parse(txtPrice.Text), ViTri = txtPosition.Text, NgayTiepNhan = dtpReceivedDate.Value, MaNVTiepNhan = cbbTaker.SelectedValue.ToString() }; int result = bUS.AddANewBook(book); if (1 == result) { MessageBox.Show("Thành công!"); } else { MessageBox.Show("Thất bại!"); } txtTitle.Text = ""; txtPosition.Text = ""; txtPrice.Text = ""; }