Adding Elements, Attributes, and Nodes to an XML Tree

You can add content (elements, attributes, comments, processing instructions, text, and CDATA) to an existing XML tree.

Methods for Adding Content

The following methods add child content to an XElement or an XDocument:

Method	Description
Add	Adds content at the end of the child content of the XContainer.
AddFirst	Adds content at the beginning of the child content of the XContainer.

The following methods add content as sibling nodes of an XNode. The most common node to which you add sibling content is XElement, although you can add valid sibling content to other types of nodes such as XText or XComment.

Method	Description
AddAfterSelf	Adds content after the XNode.
AddBeforeSelf	Adds content before the XNode.

Example

Description

The following example creates two XML trees, and then modifies one of the trees.

Code

XElement srcTree = new XElement("Root", 
    new XElement("Element1", 1),
    new XElement("Element2", 2),
    new XElement("Element3", 3),
    new XElement("Element4", 4),
    new XElement("Element5", 5)
);
XElement xmlTree = new XElement("Root",
    new XElement("Child1", 1),
    new XElement("Child2", 2),
    new XElement("Child3", 3),
    new XElement("Child4", 4),
    new XElement("Child5", 5)
);
xmlTree.Add(new XElement("NewChild", "new content"));
xmlTree.Add(
    from el in srcTree.Elements()
    where (int)el > 3
    select el
);
// Even though Child9 does not exist in srcTree, the following statement will not
// throw an exception, and nothing will be added to xmlTree.
xmlTree.Add(srcTree.Element("Child9"));
Console.WriteLine(xmlTree);

Dim srcTree As XElement = _
    <Root>
        <Element1>1</Element1>
        <Element2>2</Element2>
        <Element3>3</Element3>
        <Element4>4</Element4>
        <Element5>5</Element5>
    </Root>
Dim xmlTree As XElement = _
    <Root>
        <Child1>1</Child1>
        <Child2>2</Child2>
        <Child3>3</Child3>
        <Child4>4</Child4>
        <Child5>5</Child5>
    </Root>

xmlTree.Add(<NewChild>new content</NewChild>)
xmlTree.Add( _
    From el In srcTree.Elements() _
    Where CInt(el) > 3 _
    Select el)

' Even though Child9 does not exist in srcTree, the following statement
' will not throw an exception, and nothing will be added to xmlTree.
xmlTree.Add(srcTree.Element("Child9"))
Console.WriteLine(xmlTree)

Comments

This code produces the following output:

<Root>
  <Child1>1</Child1>
  <Child2>2</Child2>
  <Child3>3</Child3>
  <Child4>4</Child4>
  <Child5>5</Child5>
  <NewChild>new content</NewChild>
  <Element4>4</Element4>
  <Element5>5</Element5>
</Root>

See Also

Other Resources

Modifying XML Trees (LINQ to XML)

Build Date:

2012-08-02