void ThemMoi() { DataRow row = ctrl.NewRow(); row["MaHoaDon"] = txtMaHoaDon.Text; row["NhanVienLap"] = txtTenNhanVien.Text; row["MaKhachHang"] = cmbTenKhachHang.SelectedValue; row["MaNhanPhong"] = cmbMaNhanPhong.SelectedValue; row["TongTien"] = txtTongTien.Text; row["NgayLap"] = dateNgaylap.Value.Date; ctrl.Add(row); HoaDonControl hdctrl = new HoaDonControl(); if (hdctrl.LayHoaDon(txtMaHoaDon.Text) != null) { MessageBox.Show("Mã hóa đơn này đã tồn tại !", "Hoa Don", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } if (ThamSo.LaSoNguyen(txtMaHoaDon.Text)) { long so = Convert.ToInt64(txtMaHoaDon.Text); if (so >= ThamSo.LayHoaDon()) { ThamSo.GanHoaDon(so + 1); } } ctrl.Update(); DataTable tblCTHD = (DataTable)bindingNavigator1.BindingSource.DataSource; ctctrl.Update(); ctrl.Save(); ctctrl.Save(); khctrl.Save(); pnctrl.Save(); }