private void btnSave_Click(object sender, EventArgs e) { int id = int.Parse(dataGridView1.SelectedRows[0].Cells["requestID"].Value.ToString()); Request re = RequestDAO.getRequestByRequestID(id); re.MaID = m.MaID; re.DateReply = DateTime.Now.ToString(); re.Reply = txtReplyContent.Text; RequestDAO.Update(re); MessageBox.Show("Reply Success"); DataTable dt = RequestDAO.GetDataTable(); DataView dv = new DataView(dt); string filter = ""; if (comboBox1.SelectedIndex == 1) { filter = "maID is not null"; } if (comboBox1.SelectedIndex == 0) { filter = "maID is null"; } dv.RowFilter = filter; dataGridView1.DataSource = dv; btnSave.Enabled = false; txtReplyContent.Enabled = false; txtReplyContent.Text = ""; btnCancel.Enabled = false; btnReply.Enabled = true; }