ListViewItem lvi = new ListViewItem(IDCode);
lvi.Tag = (string)dataReader["IDCode"];
ListView1.Items.Add(lviUsers);
ListView1.SubItems.AddRange(new string[] { name, nation, valiDate, birthday, address, department, sex });
ListView1.SelectedItems[0].Tag //所有选中项的第一个
ListView1.SelectedItems.Count//所有选中项的个数