XmlElement to XElement and XmlDocument to XDocument

Convert-Xml-to-Xml.Linq.cs

public static XElement ToXElement(this XmlElement xmlelement)
{
    return XElement.Load(xmlelement.CreateNavigator().ReadSubtree());
}

public static XmlDocument ToXmlDocument(this XDocument xdoc)
{
    var xmldoc = new XmlDocument();
    xmldoc.Load(xdoc.CreateReader());
    return xmldoc;
}


//XmlDocument to XDocument
XDocument xDoc = XDocument.Load(new XmlNodeReader(xmlDoc));
//To get the root element from the XDocument you use xDoc.Root


//here's explicitly a sample to convert XDocument to XElement:
 XDocument doc = XDocument.Load(...);
 return doc.Root;
//BUT remember this acts on the same reference, i.e. if you edit the resultant XElement, the changes are reflected on XDocument doc as well. This may or may not be desired



//Simple conversion from XDocument to XElement
XElement cvtXDocumentToXElement(XDocument xDoc)
{
    XElement xmlOut = XElement.Parse(xDoc.ToString());
    return xmlOut;
}
//BUT remember, this creates a completely new instance of XElement, i.e. changes made to XElement wont be reflected on XDocument. This may or may not be desired