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: