Merge XML files in a XDocument

I tried a bit myself :

var MyDoc = XDocument.Load("File1.xml");MyDoc.Root.Add(XDocument.Load("File2.xml").Root.Elements());

I dont know whether it is good or bad, but it works fine to me :-)

Being pragmatic, XDocument vs XmLDocument isn't all-or-nothing (unless you are on Silverlight) - so if XmlDoucument does something you need, and XDocument doesn't, then perhaps use XmlDocument (with ImportNode etc).

That said, even with XDocument, you could presumably use XNode.ReadFrom to import each, then simply .Add it to the main collection.

Of course, if the files are big, XmlReader/XmlWriter might be more efficient... but more complex. Fortunately, XmlWriter has a WriteNode method that accepts an XmlReader, so you can navigate to the first child in the XmlReader and then just blitz it to the output file. Something like:

    static void AppendChildren(this XmlWriter writer, string path)    {        using (XmlReader reader = XmlReader.Create(path))        {            reader.MoveToContent();            int targetDepth = reader.Depth + 1;            if(reader.Read()) {                while (reader.Depth == targetDepth)                {                    writer.WriteNode(reader, true);                }                            }        }    }

Merge all xml files from dir to one XDocument

public static XDocument MergeDir(string xmlDir){    XDocument xdoc = XDocument.Parse("<root></root>");    System.IO.DirectoryInfo directory = new DirectoryInfo(xmlDir);    if (directory.Exists)    {        foreach (System.IO.FileInfo file in directory.GetFiles())        {            if (file.Extension == ".xml")            {                xdoc.Root.Add(XDocument.Load(file.FullName).Root.Elements());            }        }    }    return xdoc;}