C#

void SomeMethod( FileInfo info )
{
   StreamReader reader = new StreamReader( info.OpenRead() );
   System.Text.Encoding encoding = reader.CurrentEncoding; // UTF8!?
   string data = reader.ReadToEnd();
   reader.Close();
   
   data = Massage(data);
   
   StreamWriter writer = new StreamWriter( info.OpenWrite(), encoding );
   writer.write(data);
   writer.Close();
}

void SomeMethod( FileInfo info )
{
   // Use the filename instead of OpenRead()):
   StreamReader reader = new StreamReader( info.FullPath );
   System.Text.Encoding encoding = reader.CurrentEncoding; // Unicode!
   string data = reader.ReadToEnd();
   reader.Close();
   
   data = Massage(data);
   
   StreamWriter writer = new StreamWriter( info.OpenWrite(), encoding );
   writer.write(data);
   writer.Close();
}

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protected override void Dispose(bool disposing)
{
  PersistToRegistry();
  base.Dispose(disposing);
}

string path = Path.GetDirectoryName(Application.StartupPath);
path = Path.Combine(path, "help.pdf");
Process.Start(path);

ProcessStartInfo psi = new ProcessStartInfo("file.pdf");
psi.UseShellExecute = true;
psi.Verb = "open";
Process.Start(psi);