private void mnu_Add_Click(object sender, EventArgs e)
        {
            FrmLR280Detail frm = new FrmLR280Detail();

            if (frm.ShowDialog() == DialogResult.OK)
            {
                LR280Item item = frm.LR280Item;
                if (FindRow(item.Comport) >= 0)
                {
                    MessageBox.Show("串口号为 " + item.Comport + " 的读卡器已经存在");
                }
                else
                {
                    int row = dataGridView1.Rows.Add();
                    ShowItemOnRow(dataGridView1.Rows[row], item);
                }
            }
        }
 private void mnu_Update_Click(object sender, EventArgs e)
 {
     if (dataGridView1.SelectedRows.Count == 1)
     {
         FrmLR280Detail frm = new FrmLR280Detail();
         frm.LR280Item = dataGridView1.SelectedRows[0].Tag as LR280Item;
         if (frm.ShowDialog() == DialogResult.OK)
         {
             LR280Item item = frm.LR280Item;
             var       row  = FindRow(item.Comport);
             if (row >= 0 && row != dataGridView1.SelectedRows[0].Index)
             {
                 MessageBox.Show("串口号为 " + item.Comport + " 的读卡器已经存在");
             }
             else
             {
                 ShowItemOnRow(dataGridView1.SelectedRows[0], item);
             }
         }
     }
 }