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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)

'Declaration
<ExtensionAttribute> _
Public Shared Function Descendants(Of T As XContainer) ( _
	source As IEnumerable(Of T) _
) As IEnumerable(Of XElement)

Type Parameters

T

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

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.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(Of T). When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

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>

.NET Framework

Supported in: 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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