Converting XDocument to XmlDocument and vice versa

Question

It's a very simple problem that I have. I use XDocument to generate an XML file. I then want to return it as a XmlDocument class. And I have an XmlDocument variable which I need to convert back to XDocument to append more nodes.

So, what is the most efficient method to convert XML between XDocument and XmlDocument? (Without using any temporary storage in a file.)

Answer 1

You can use the built in xDocument.CreateReader() and an XmlNodeReader to convert back and forth.

Putting that into an Extension method to make it easier to work with.

using System;
using System.Xml;
using System.Xml.Linq;

namespace MyTest
{
    internal class Program
    {
        private static void Main(string[] args)
        {

            var xmlDocument = new XmlDocument();
            xmlDocument.LoadXml("<Root><Child>Test</Child></Root>");

            var xDocument = xmlDocument.ToXDocument();
            var newXmlDocument = xDocument.ToXmlDocument();
            Console.ReadLine();
        }
    }

    public static class DocumentExtensions
    {
        public static XmlDocument ToXmlDocument(this XDocument xDocument)
        {
            var xmlDocument = new XmlDocument();
            using(var xmlReader = xDocument.CreateReader())
            {
                xmlDocument.Load(xmlReader);
            }
            return xmlDocument;
        }

        public static XDocument ToXDocument(this XmlDocument xmlDocument)
        {
            using (var nodeReader = new XmlNodeReader(xmlDocument))
            {
                nodeReader.MoveToContent();
                return XDocument.Load(nodeReader);
            }
        }
    }
}

Sources:

• http://msdn.microsoft.com/en-us/library/bb356384.aspx
• http://geekswithblogs.net/aspringer/archive/2009/07/01/xdocument-extension.aspx

Answer 2

For me this single line solution works very well

XDocument y = XDocument.Parse(pXmldoc.OuterXml); // where pXmldoc is of type XMLDocument