C#

public class MyTextBox : TextBox {

  public override bool PreProcessMessage(ref Message msg)
  {
    //do your stuff here
  }
}

public class UTF8StringWriter : StringWriter 
{
  public override Encoding Encoding
  {
    get { return System.Text.Encoding.UTF8;}
  }
}

public XmlTextWriter_(TextWriter w, Encoding enc) {
  this = new XmlTextWriter_();
  this.textWriter = w;
  this.encoding = enc;
  this.xmlEncoder = new XmlTextEncoder(w, this.encoding);
  this.xmlEncoder.QuoteChar = this.quoteChar;
}

public class XmlTextWriter_ : System.Xml.XmlTextWriter
{
  ...
  // your constructor here
}

public class Class1
{
   public int number;
   public string name;

   [STAThread]
   static void Main(string[] args)
   {
      Class1 c = new Class1();
      c.name = "Hello";
      c.number = 1;

      XmlSerializer xser = new XmlSerializer(c.GetType());
      FileStream fs = File.Open("Class.xml", FileMode.OpenOrCreate);
      xser.Serialize(fs, c);

      fs.Close();
   }
}

<?xml version="1.0"?>
<Class1 xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <number>1</number>
  <name>Hello</name>
</Class1>