合并多个xml文件

var xml1 = XDocument.Load("file1.xml"); 
var xml2 = XDocument.Load("file2.xml"); 
//Combine and remove duplicates
 var combinedUnique = xml1.Descendants("AllNodes") .Union(xml2.Descendants("AllNodes")); 
//Combine and keep duplicates 
var combinedWithDups = xml1.Descendants("AllNodes") .Concat(xml2.Descendants("AllNodes"));