Serializzare un oggetto tramite ISerializable (SOAP)

[Serializable]
using System.Runtime.Serialization;

[Serializable]
public class Note : ISerializable
{
  private string _title;
  public string Title
  {
    get { return _title; }
    set { _title = value; }
  }

  private string  _body;
  public string  Body
  {
    get { return _body; }
    set { _body = value; }
  }

  private int _version;
  public int Version
  {
    get { return _version; }
    set { _version = value; }
  }

  public Note()
  {
  }

  //costruttore richiesto dalla serializzazione
  protected Note(SerializationInfo info, StreamingContext context)
  {
    this.Title = info.GetString("MyTitle");
    this.Body = info.GetString("MyBody");
    this.Version = info.GetInt32("MyVersion");
  }

  // ISerializable Members
  public void GetObjectData(SerializationInfo info, StreamingContext context)
  {
    info.AddValue("MyTitle", this.Title);
    info.AddValue("MyBody", this.Body);
    info.AddValue("MyVersion", this.Version);
  }
}

Note note = new Note();
private const string FILENAME = "note.xml";

private void Deserialize()
{
    if (File.Exists(FILENAME) == true)
    {
        SoapFormatter sf = new SoapFormatter();
        using (Stream strm = File.Open(FILENAME, FileMode.Open))
        {
            if (strm.Length > 0)
            {
                try
                {
                    //popola l'oggetto Note
                    note = (Note)sf.Deserialize(strm);
                }
                catch (System.Xml.XmlException ex)
                {
                    //MessageBox.Show(ex.Message);
                }
                catch (System.Reflection.TargetInvocationException ex)
                {
                  //nome elemento errato
                }
            }
        }
    }
}

private void Serialize()
{
    SoapFormatter sf = new SoapFormatter();
    using (Stream strm = File.Open(FILENAME, FileMode.Create, FileAccess.Write))
    {
        sf.Serialize(strm, note);
    }
}