private void btn_Delete_Click(object sender, RoutedEventArgs e)
        {
            if (dgrd_View.SelectedItem == null)
            {
                return;
            }
            dsHandleRecord record = (dsHandleRecord)dgrd_View.SelectedItem;

            if (HelperDatabase.DeleteRecord(record.MacId))
            {
                MessageBox.Show("删除成功!");
            }
        }