老外编的程序（一）－－XMLDocument转为String

        static public string XmlDocumentToString(ref XmlDocument doc)
        {
            MemoryStream stream = new MemoryStream();
            XmlTextWriter writer = new XmlTextWriter(stream, null);
            writer.Formatting = Formatting.Indented;
            doc.Save(writer);

            StreamReader sr = new StreamReader(stream, System.Text.Encoding.UTF8);
            stream.Position = 0;
            string xmlString = sr.ReadToEnd();
            sr.Close();
            stream.Close();

            return xmlString;
        }

原文转自：http://www.ltesting.net