C#

static void Main(string[] args)
{
    XDocument x = XDocument.Parse(sXml);
    Reorder(x.FirstNode);
    x.Save(newFileName);
}

private static void Reorder(XNode node)
{
    var kids = (from nd in node.XPathSelectElements("*") orderby nd.Name.LocalName select nd).ToList();
    if (kids.Count>1)
    {
        (node as XElement).ReplaceNodes(kids);
    }
    kids.ForEach(f => Reorder(f));
}

static void Main(string[] args)
{
    string newFileName = "c:\\myfilename.xml";

    XmlDocument docSource = new XmlDocument();
    docSource.LoadXml(XML);
    Reorder(docSource.DocumentElement);
    docSource.Save(newFileName);
}


private static void Reorder(XmlNode node)
{
    SortedList<string, XmlNode> childlist = SortedChildNodes(node);
    node.RemoveAll();
    for (int i = 0; i < childlist.Count; i++)
    {
        Reorder(node.AppendChild(childlist.Values[i]));
    }

}
static SortedList<string, XmlNode> SortedChildNodes(XmlNode node)
{
    SortedList<string, XmlNode> ret = new SortedList<string, XmlNode>();
    for (int i = 0; i < node.ChildNodes.Count; i++)
    {
        string name = node.ChildNodes[i].Name;
        XmlNode nd = node.ChildNodes[i];
        ret.Add(name, nd);
    }
    return ret;
}

Luc Pattyn wrote:

- make sure you don't create a lot of objects while painting controls (assuming some are user-drawn);