Extensions.Descendants<T> Method (IEnumerable<T>)

 

Returns a collection of elements that contains the descendant elements of every element and document in the source collection.

Namespace:   System.Xml.Linq
Assembly:  System.Xml.Linq (in System.Xml.Linq.dll)

public static IEnumerable<XElement> Descendants<T>(
	this IEnumerable<T> source
)
where T : XContainer

Parameters

source
Type: System.Collections.Generic.IEnumerable<T>

An IEnumerable<T> of XContainer that contains the source collection.

Return Value

Type: System.Collections.Generic.IEnumerable<XElement>

An IEnumerable<T> of XElement that contains the descendant elements of every element and document in the source collection.

Type Parameters

T

The type of the objects in source, constrained to XContainer.

Visual Basic users can use the integrated XML descendant axis to retrieve the descendant elements of a collection. However, the integrated axis only retrieves descendants with a specified name. If Visual Basic users want to retrieve all descendants, then they must use this axis method explicitly.

This method uses deferred execution.

The following example retrieves a collection of elements, and then uses this axis method to retrieve all descendent elements of every item in the collection of elements.


                XElement xmlTree = XElement.Parse(
@"<Root>
    <Para>
        <t>This is some text </t>
        <b>
            <t>where</t>
        </b>
        <t> all of the nodes must be concatenated. </t>
    </Para>
    <Para>
        <t>This is a second sentence.</t>
    </Para>
</Root>");

IEnumerable<XElement> elList =
    from el in xmlTree.Elements("Para").Descendants()
    select el;

foreach (XElement el in elList)
    Console.WriteLine(el);

This example produces the following output:

<t>This is some text </t>
<b>
  <t>where</t>
</b>
<t>where</t>
<t> all of the nodes must be concatenated. </t>
<t>This is a second sentence.</t>

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 = XElement.Parse(
@"<Root xmlns='http://www.adventure-works.com'>
    <Para>
        <t>This is some text </t>
        <b>
            <t>where</t>
        </b>
        <t> all of the nodes must be concatenated. </t>
    </Para>
    <Para>
        <t>This is a second sentence.</t>
    </Para>
</Root>");

IEnumerable<XElement> elList =
    from el in xmlTree.Elements(aw + "Para").Descendants()
    select el;

foreach (XElement el in elList)
    Console.WriteLine(el);

This example produces the following output:

<t xmlns="http://www.adventure-works.com">This is some text </t>
<b xmlns="http://www.adventure-works.com">
  <t>where</t>
</b>
<t xmlns="http://www.adventure-works.com">where</t>
<t xmlns="http://www.adventure-works.com"> all of the nodes must be concatenated. </t>
<t xmlns="http://www.adventure-works.com">This is a second sentence.</t>

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top
Show: