private void btRefresh_Click(object sender, EventArgs e)

        {

            

            

            //start put sqldata into list view

            try

            {

                

                SqlConnection sc = new SqlConnection();//create SQL connection object                

                sc.ConnectionString = strConn;// 

                sc.Open();//Open connection



                //To store SQL Select command

                string tempCommand = "select Types,RootVer from VerControl";

                SqlCommand sd = new SqlCommand(tempCommand, sc);

                SqlDataReader sdr = sd.ExecuteReader();

                lvFile.Items.Clear();

                while (sdr.Read())//if have data from VerControl

                {

                    //set properties of list view

                    lvFile.View = View.Details;

                    lvFile.FullRowSelect = true;

                    lvFile.GridLines = true;

                    this.lvFile.Scrollable = true;

                    this.lvFile.MultiSelect = false;

                    this.lvFile.HeaderStyle = ColumnHeaderStyle.Clickable;



                    for (int i = 0; i < sdr.FieldCount; i++)

                    {

                        //读出数据来,   自动生成列标头 

                        ColumnHeader ch = new ColumnHeader();

                        ch.Text = sdr.GetName(i).ToString();

                        this.lvFile.Columns.Add(ch);

                        //循环显示列 

                        ListViewItem lvi = new ListViewItem();

MessageBox.Show(sdr.GetValue(i).ToString());//检查从数据库取值，两个字段都取到值

                        lvi.SubItems[i].Text = sdr.GetValue(i).ToString();//catch显示这行出错

                        this.lvFile.Items.Add(lvi);

                    } 

                    lvFile.Show();

                    if (lvFile.Items.Count == 0)

                    {

                        MessageBox.Show("List View is Empty!");

                    }



                }

                sdr.Close();

                

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.ToString());

            }

            

        }