C# 텍스트문 입출력~! 파일열기 파일저장

  private void 열기ToolStripMenuItem_Click(object sender, EventArgs e)
  {
   if (openFileDialog1.ShowDialog() == DialogResult.OK)
   {

    Stream str = openFileDialog1.OpenFile();
    StreamReader reader = new StreamReader(str);
    textBox1.Text= reader.ReadToEnd();
    reader.Close();
    this.Text = openFileDialog1.FileName;
    
   }
  }

  private void 저장ToolStripMenuItem_Click(object sender, EventArgs e)
  {

   if (saveFileDialog1.ShowDialog() == DialogResult.OK)
   {
    string savename = saveFileDialog1.FileName;
    StreamWriter writer = new StreamWriter(savename);
    writer.Write(textBox1.Text);
    writer.Close();
    this.Text = saveFileDialog1.FileName;
   }
  }