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Extensions.AncestorsAndSelf Method (IEnumerable(Of XElement), XName)

Returns a filtered collection of elements that contains every element in the source collection, and the ancestors of every element in the source collection. Only elements that have a matching XName are included in the collection.

Namespace:  System.Xml.Linq
Assemblies:   System.Xml.XDocument (in System.Xml.XDocument.dll)
  System.Xml.Linq (in System.Xml.Linq.dll)

'Declaration
<ExtensionAttribute> _
Public Shared Function AncestorsAndSelf ( _
	source As IEnumerable(Of XElement), _
	name As XName _
) As IEnumerable(Of XElement)

Parameters

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

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

name
Type: System.Xml.Linq.XName

The XName to match.

Return Value

Type: System.Collections.Generic.IEnumerable(Of XElement)
An IEnumerable(Of T) of XElement that contains every element in the source collection, and the ancestors of every element in the source collection. Only elements that have a matching XName are included in the collection.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(Of XElement). 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).

If multiple nodes in the source collection have the same ancestor with a matching XName, the ancestor will be included multiple times in the result collection.

This method uses deferred execution.

The following example retrieves a collection of the great grandchildren elements. It then uses this axis method to retrieve all self and ancestors of all elements in the collection that match a specified XName.

Dim xmlTree As XElement = _
    <Root>
        <Child1>
            <GrandChild1>
                <GreatGrandChild1>content</GreatGrandChild1>
            </GrandChild1>
        </Child1>
        <Child2>
            <GrandChild2>
                <GreatGrandChild2>content</GreatGrandChild2>
            </GrandChild2>
        </Child2>
    </Root>
                          
Dim greatGrandChildren = From el In xmlTree.Descendants _
                         Where el.Name.LocalName.StartsWith("Great") _
                         Select el

Console.WriteLine("Great Grand Children Elements")
Console.WriteLine("----")

For Each de As XElement In greatGrandChildren
    Console.WriteLine(de.Name)
Next

Dim allAncestors = From el In greatGrandChildren.AncestorsAndSelf("GreatGrandChild1") _
                   Select el

Console.WriteLine("")
Console.WriteLine("Ancestors and Self")
Console.WriteLine("----")

For Each de As XElement In allAncestors
    Console.WriteLine(de.Name)
Next

This example produces the following output:

Great Grand Children Elements
----
GreatGrandChild1
GreatGrandChild2

Ancestors and Self
----
GreatGrandChild1

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>
                <Child1>
                    <GrandChild1>
                        <GreatGrandChild1>content</GreatGrandChild1>
                    </GrandChild1>
                </Child1>
                <Child2>
                    <GrandChild2>
                        <GreatGrandChild2>content</GreatGrandChild2>
                    </GrandChild2>
                </Child2>
            </Root>

        Dim greatGrandChildren = From el In xmlTree.Descendants _
                                 Where el.Name.LocalName.StartsWith("Great") _
                                 Select el

        Console.WriteLine("Great Grand Children Elements")
        Console.WriteLine("----")

        For Each de As XElement In greatGrandChildren
            Console.WriteLine(de.Name)
        Next

        Dim allAncestors = From el In greatGrandChildren.AncestorsAndSelf(GetXmlNamespace() + "GreatGrandChild1") _
                           Select el

        Console.WriteLine("")
        Console.WriteLine("Ancestors and Self")
        Console.WriteLine("----")

        For Each de As XElement In allAncestors
            Console.WriteLine(de.Name)
        Next
    End Sub
End Module

This example produces the following output:

Great Grand Children Elements
----
{http://www.adventure-works.com}GreatGrandChild1
{http://www.adventure-works.com}GreatGrandChild2

Ancestors and Self
----
{http://www.adventure-works.com}GreatGrandChild1

.NET Framework

Supported in: 4.6, 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

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: 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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