If you have an XML string with characters such as ampersands that must be encoded, a method in the System.Security namespace will do the job. System.Security.SecurityElement.Escape("\"Eric\" &\'") returns ""Eric" & <Wilma>'".

Of course you could write your own method to encode <, >, ", ', and &, but this is the sort of thing the platform should do for you. It's puzzling that this method is not in the System.Xml namespace.

public static string XmlEncode()
{
  var text = "\"Eric\" & \'";

  return System.Security.SecurityElement.Escape(text);
}