c# listview 导入txt 添序号

c# listview 导入txt 加序号

我有一段数据

123-123

456-456

789-789

用openfiledialog导入listview，需要分割，

然后在前面加一栏序号，怎么实现啊

如图：


------解决方案--------------------
请指教。。。

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.IO;


namespace WindowsFormsApplication22

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }


        private void Form1_Load(object sender, EventArgs e)

        {

            int couns=0;

            listView1.View = View.Details;

            ColumnHeader ch1 = new ColumnHeader();

            ch1.Text = "序号";

            ColumnHeader ch2=new ColumnHeader();

            ch2.Text = "账号";

            ColumnHeader ch3=new ColumnHeader();

            ch3.Text = "密码";

            listView1.Columns.Add(ch1);

            listView1.Columns.Add(ch2);

            listView1.Columns.Add(ch3);

            OpenFileDialog file = new OpenFileDialog();

            if (file.ShowDialog() == DialogResult.OK) {

                FileStream fs=new FileStream(file.FileName,FileMode.Open);

                StreamReader sr = new StreamReader(fs);

                sr.BaseStream.Seek(0, SeekOrigin.Begin);

                while (!sr.EndOfStream) {       

                    string[] ss = sr.ReadLine().Split(new char[] { '-' }, StringSplitOptions.RemoveEmptyEntries);