Reading Text from Files (C#.net)

private void button2_Click(object sender, EventArgs e)
{
try
{
 string buffer;
 StringBuilder stb = new StringBuilder();
 StreamReader strmRdr = File.OpenText("c:\\testfile.txt");
 while ((buffer = strmRdr.ReadLine()) != null)
 {
  stb.Append(buffer);
  stb.Append(Environment.NewLine);
 }
 textBox1.Text = stb.ToString();
 strmRdr.Close();
}
catch (IOException ex)
{
 Console.WriteLine("Error in handling file!\n" + ex.Message.ToString());
}
}