void loadDS() { List <HoaDonDTO> dsHD = HoaDonBUS.GetDSHD(); dgvDSHD.DataSource = dsHD; for (int i = 0; i < dgvDSHD.Rows.Count; i++) { dgvDSHD.Rows[i].Cells[0].Value = i + 1; } btnThem.Enabled = true; btnSua.Enabled = true; txtMaMoi.Enabled = true; btnLuu.Enabled = false; }