Extensions.Descendants(Of T) Method (IEnumerable(Of 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)

<ExtensionAttribute>
Public Shared Function Descendants(Of T As XContainer) (
	source As IEnumerable(Of T)
) As IEnumerable(Of XElement)

Parameters

source
Type: System.Collections.Generic.IEnumerable(Of T)

An IEnumerable(Of T) of XContainer that contains the source collection.

Return Value

Type: System.Collections.Generic.IEnumerable(Of XElement)

An IEnumerable(Of 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.


                Dim xmlTree As XElement = _
    <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>

Dim elList = From el In xmlTree.<Para>.Descendants _
                        Select el

For Each el As XElement In elList
    Console.WriteLine(el)
Next

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.


                Imports <xmlns="http://www.adventure-works.com">

Module Module1
    Sub Main()
        Dim xmlTree As XElement = _
            <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>

        Dim elList = From el In xmlTree.<Para>.Descendants _
                                Select el

        For Each el As XElement In elList
            Console.WriteLine(el)
        Next
    End Sub
End Module

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
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