Serialize an arbitary string to XML in .NET

What is the best way to serialize an arbitary string (into an XML attribute or XML node) to a XML stream so that the XML stays valid (special characters, newlines etc. must be encoded somehow).

From stackoverflow

• I would simply use either a DOM (such as XmlDocument or XDocument), or for huge files, XmlWriter:

          XDocument xdoc = new XDocument(new XElement("xml", "a < b & c"));
          Console.WriteLine(xdoc.ToString());
  
          XmlDocument xmldoc = new XmlDocument();
          XmlElement root = xmldoc.CreateElement("xml");
          xmldoc.AppendChild(root).InnerText = "a < b & c";
          Console.WriteLine(xmldoc.OuterXml);
  
          StringBuilder sb = new StringBuilder();
          XmlWriterSettings settings = new XmlWriterSettings();
          settings.OmitXmlDeclaration = true;
          using (XmlWriter xw = XmlWriter.Create(sb, settings))
          {
              xw.WriteElementString("xml", "a < b & c");
          }
          Console.WriteLine(sb);
  

• Isn't that exactly what CDATA is meant to be used for in XML? All you need to watch out for is that your data doesn't contain "]]>", or that you escape them somehow using the time-honored C technique:

  Encoding:
      '\' becomes '\\'
      ']' becomes '\]'
  Decoding:
      '\]' becomes ']'
      '\\' becomes '\'