a c# function to write an XML; was written for generation of a config file for Microsoft Research's Management of Access Control in the Enterprise (MACE). I will be publishing the repo (a wrapper for the datacollector executable in the MACE suite) when it is sufficiently functional.

xmlwriter.cs

public static void WriteXML(string filename, Dictionary<string, string> commandoptions)
{

    //if the file exists, then move it to DataCollector.exe.config.bak
    if (File.Exists(filename))
    {
        File.Move(filename, filename + ".bak");
    }

    //write the XML document//
    // http://csharp.net-informations.com/xml/how-to-create-xml.htm
    // http://www.dotnetperls.com/xmltextwriter
    // using XMLWriter over XMLTextWriter: http://blogs.msdn.com/b/xmlteam/archive/2011/10/08/the-world-has-moved-on-have-you-xml-apis-you-should-avoid-using.aspx
    // http://msdn.microsoft.com/en-us/library/kkz7cs0d.aspx


    XmlWriterSettings settings = new XmlWriterSettings();
    settings.Indent = true;
    settings.IndentChars = ("    ");
    using (XmlWriter writer = XmlWriter.Create(filename, settings))
    {
        // Write XML data.
        writer.WriteStartElement("configuration");
        writer.WriteStartElement("appSettings");
        foreach (KeyValuePair<string, string> option in commandoptions)
        {
            writer.WriteStartElement("add");
            writer.WriteAttributeString("key", option.Key);
            writer.WriteAttributeString("value", option.Value);
            writer.WriteEndElement();
        }
        writer.WriteEndElement();
        writer.WriteEndElement();
        writer.Flush();
    }
}