This extension method is useful when you want to retrieve all elements with a specified name at a particular depth. This is easy if the document is very regular, but if the document is irregular, it can be a bit more difficult. In the following example, we want to retrieve all aaa elements that are children of Item elements. A given Item element may or may not contain an aaa element. This is easily accomplished using this extension method, as follows:
XElement xmlTree = new XElement("Root",
new XElement("Item",
new XElement("aaa", 1),
new XElement("bbb", 2)
),
new XElement("Item",
new XElement("ccc", 3),
new XElement("aaa", 4)
),
new XElement("Item",
new XElement("ddd", 5),
new XElement("eee", 6)
)
);
IEnumerable<XElement> allGrandChildren =
from el in xmlTree.Elements("Item").Elements("aaa")
select el;
foreach (XElement el in allGrandChildren)
Console.WriteLine(el);
Dim xmlTree As XElement = _
<Root>
<Item>
<aaa>1</aaa>
<bbb>2</bbb>
</Item>
<Item>
<ccc>3</ccc>
<aaa>4</aaa>
</Item>
<Item>
<ddd>5</ddd>
<eee>6</eee>
</Item>
</Root>
Dim allGrandChildren = From el In xmlTree.<Item>.<aaa> _
Select el
For Each el As XElement In allGrandChildren
Console.WriteLine(el)
Next
This example produces the following output:
<aaa>1</aaa>
<aaa>4</aaa>
The following is the same example, but in this case the XML is in a namespace. For more information, see Working with XML Namespaces.
XNamespace aw = "http://www.adventure-works.com";
XElement xmlTree = new XElement(aw + "Root",
new XElement(aw + "Item",
new XElement(aw + "aaa", 1),
new XElement(aw + "bbb", 2)
),
new XElement(aw + "Item",
new XElement(aw + "ccc", 3),
new XElement(aw + "aaa", 4)
),
new XElement(aw + "Item",
new XElement(aw + "ddd", 5),
new XElement(aw + "eee", 6)
)
);
IEnumerable<XElement> allGrandChildren =
from el in xmlTree.Elements(aw + "Item").Elements(aw + "aaa")
select el;
foreach (XElement el in allGrandChildren)
Console.WriteLine(el);
Imports <xmlns="http://www.adventure-works.com">
Module Module1
Sub Main()
Dim xmlTree As XElement = _
<Root>
<Item>
<aaa>1</aaa>
<bbb>2</bbb>
</Item>
<Item>
<ccc>3</ccc>
<aaa>4</aaa>
</Item>
<Item>
<ddd>5</ddd>
<eee>6</eee>
</Item>
</Root>
Dim allGrandChildren = From el In xmlTree.<Item>.<aaa> _
Select el
For Each el As XElement In allGrandChildren
Console.WriteLine(el)
Next
End Sub
End Module
This example produces the following output:
<aaa xmlns="http://www.adventure-works.com">1</aaa>
<aaa xmlns="http://www.adventure-works.com">4</aaa>