I’m encountering an issue with using LINQ to manipulate XML. To demonstrate, I created a simple test with two XML files. The problem arises after I add a node; altering its information doesn’t change the added node. However, if I add this node along with its parent node, it does change. I’m puzzled because I didn’t create a new instance at all. Any assistance would be appreciated.
test2.xml

<?xml version="1.0" encoding="utf-8"?>
<haha>
</haha>

test1.xml

<?xml version="1.0" encoding="utf-8"?>
<root id="100">
  <node id="1" name="a"/>
  <node id="2" name="b"/>
  <node id="3" name="c"/>
</root>

code

XElement x1 = new XElement(XElement.Load("D:\test1.xml"));
XElement x2 = new XElement(XElement.Load("D:\test2.xml"));
XElement node1=x1.Element("node");
x2.Add(node1);
x2.Add(x1);
node1.Attribute("id").Value = "33";

result x2

<haha>
  <node id="1" name="a" />
  <root id="100">
    <node id="33" name="a" />
    <node id="2" name="b" />
    <node id="3" name="c" />
  </root>
</haha>