C#打开一个文本文件并读写

OpenFileDialog OFD = new OpenFileDialog();
OFD.Title = "打开第一个文本文件";
OFD.FileName = "*.txt";
OFD.InitialDirectory = WorkSpacePath;
if (OFD.ShowDialog() == DialogResult.OK)
{
FileInfo fi = new FileInfo(OFD.FileName);
StreamReader sr = fi.OpenText();
while (sr.Peek() > 0)
{
listBox1.Items.Add(sr.ReadLine());
}
sr.Close();
textBox1.Text = OFD.FileName;
this.statusStrip1.Items[1].Text = listBox1.Items.Count.ToString();
}

string Path = Application.StartupPath;
FileStream fs = new FileStream(Path + "\\path.dll", FileMode.Create, FileAccess.Write);
StreamWriter sw = new StreamWriter(fs);
sw.WriteLine(path08);
sw.WriteLine(path07);
sw.WriteLine(path06);
sw.WriteLine(WorkSpacePath);
sw.WriteLine(EFDCPath);
sw.WriteLine(path09);
sw.Close();
fs.Close();