private void cmdThem_Click(object sender, RoutedEventArgs e)
 {
    // this.DialogResult = true;
     frmnhapxa frm = new frmnhapxa(false);
     this.DialogResult = false;
     frm.Show();
 }
 private void tableView1_RowDoubleClick(object sender, DevExpress.Xpf.Grid.RowDoubleClickEventArgs e)
 {
     frmnhapxa frm = new frmnhapxa(true);
     frm.txtmaxa.Text = gridControl1.GetFocusedRowCellValue(maxa).ToString().Trim();
     frm.txtmaxa.IsReadOnly = true;
     frm.txtten.Text = gridControl1.GetFocusedRowCellValue(ten).ToString().Trim();
     this.DialogResult = false;
     frm.Show();
 }