private void btnLuu_Click(object sender, EventArgs e) { int sl = int.Parse(txtSL.Text); long gia = long.Parse(txtGiaNhap.Text); long thanhtien = (long)sl * gia; long masp = long.Parse(cbbMaSP.SelectedValue.ToString()); CTPNDTO ctpn = new CTPNDTO(maphieu, masp, sl, gia, thanhtien); PhieuNhapBUS.InsertCTPN(ctpn); dgvNhapHang.DataSource = PhieuNhapBUS.GetCTPN(maphieu); }