C# listview控件右击导出数据到txt文本

private void 导出成功点击ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (listCount.Items.Count == 0)
            {
                MessageBox.Show("列表为空!");
            }
            else {
                List<string> list = new List<string>();
                foreach (ListViewItem item in listCount.Items)
                {
                    string temp = item.SubItems[2].Text;
                    list.Add(temp);
                }
                Thread thexp = new Thread(() => export(list)) { IsBackground = true };
                thexp.Start();
            }
        }
        private void export(List<string> list)
        {
            string path = AppDomain.CurrentDomain.BaseDirectory + "url_" + Guid.NewGuid().ToString() + ".txt";
            StringBuilder sb = new StringBuilder();
            foreach (string tel in list)
            {
                sb.AppendLine(tel);
            }
            System.IO.File.WriteAllText(path, sb.ToString(), Encoding.UTF8);
            txtmsg.BeginInvoke(new Action(() => {
                string temp = "文件导出成功!文件地址:" + path;
                txtmsg.AppendText(temp.SetLog());
            }));
        }