C#读取txt数据到一个二维数组

        private void button1_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog() != DialogResult.Cancel)
            {
                FileName = openFileDialog1.FileName;
                System.IO.StreamReader readfile = new System.IO.StreamReader(FileName);
                readfile.BaseStream.Seek(0, System.IO.SeekOrigin.Begin);
                int line_total=0;//总行数

                while (readfile.ReadLine() != null)
                {
                    line_total++;
                }


                textBox3.Text = line_total.ToString();

                readfile.BaseStream.Seek(0,System.IO.SeekOrigin.Begin);
              //  string line = readfile.ReadLine();


                List<string[]> list = new List<string[]>();

                while (!readfile.EndOfStream)
                {
                    
                    string[] line = readfile.ReadLine().Split(' ');
                    string[] arr = new string[line.Length];
                    for (int i = 0; i < line.Length; i++)
                    {
                        arr[i] = Convert.ToString(line[i]);

                    }
                    list.Add(arr);
                }


                string[][] shuzu = list.ToArray();


                textBox4.Text = shuzu[0][5];
           //显示指定数据，此程序不能用shuzu[0,5],还没搞懂原因



            }
            else
                return;
        }