protected void GridView1_SelectedIndexChanged(object sender, EventArgs e) { string maSach = GridView1.SelectedRow.Cells[0].Text; s = cn.GetSachByID(maSach); if (s != null) { txtMaSach.Text = s.MaSach; txtTenSach.Text = s.TenSach; ddlNhaXuatBan.SelectedValue = s.MaNhaXuatBan; txtMoTa.Text = s.MoTa; ddlLoaiSach.SelectedValue = s.MaLoai; ddlTacGia.SelectedValue = s.MaTacGia; txtSoLuong.Text = s.SoLuong.ToString(); } }