Language

Extensions.DescendantNodes(IEnumerable) Method

Definition

Namespace:
System.Xml.Linq
Assemblies:
System.Xml.Linq.dll, System.Xml.XDocument.dll
Assemblies:
netstandard.dll, System.Xml.XDocument.dll
Assembly:
System.Xml.XDocument.dll
Assembly:
System.Xml.Linq.dll
Assembly:
netstandard.dll
Source:
Extensions.cs
Source:
Extensions.cs
Source:
Extensions.cs
Source:
Extensions.cs
Source:
Extensions.cs

Returns a collection of the descendant nodes of every document and element in the source collection.

public:
generic 
 where T : System::Xml::Linq::XContainer[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::IEnumerable ^ DescendantNodes(System::Collections::Generic::IEnumerable ^ source);
public static System.Collections.Generic.IEnumerable DescendantNodes(this System.Collections.Generic.IEnumerable source) where T : System.Xml.Linq.XContainer;
public static System.Collections.Generic.IEnumerable DescendantNodes(this System.Collections.Generic.IEnumerable source) where T : System.Xml.Linq.XContainer;
static member DescendantNodes : seq<'T (requires 'T :> System.Xml.Linq.XContainer)> -> seq (requires 'T :> System.Xml.Linq.XContainer)

Public Function DescendantNodes(Of T As XContainer) (source As IEnumerable(Of T)) As IEnumerable(Of XNode)

Type Parameters

T

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

Parameters

source
IEnumerable

An IEnumerable of XContainer that contains the source collection.

Returns

IEnumerable<XNode>

An IEnumerable of XNode of the descendant nodes of every document and element in the source collection.

Examples

The following example retrieves a collection of two elements, and then retrieves a collection of all descendant nodes for every element in the source collection. Note that the attribute of the GrandChild element is not surfaced as a node.

XElement xmlTree = XElement.Parse(
@"
    aaaText
        
        
    
    cccTextddd
");
IEnumerable nodes =
    from node in xmlTree.Elements("Child").DescendantNodes()
    select node;

foreach (XNode node in nodes)
{
    switch (node.NodeType)
    {
        case XmlNodeType.Element:
            Console.WriteLine("Element: {0}", ((XElement)node).Name);
            break;
        case XmlNodeType.Text:
            Console.WriteLine("Text: {0}", ((XText)node).Value);
            break;
        case XmlNodeType.Comment:
            Console.WriteLine("Comment: {0}", ((XComment)node).Value);
            break;
        case XmlNodeType.ProcessingInstruction:
            Console.WriteLine("PI: {0}", ((XProcessingInstruction)node).Data);
            break;
    }
}

Dim xmlTree As XElement = _

    aaaText
        
        
    
    cccTextddd


Dim nodes As IEnumerable(Of XNode) = _
    From node In xmlTree..DescendantNodes _
    Select node

For Each node As XNode In nodes
    Select Case node.NodeType
        Case XmlNodeType.Element
            Console.WriteLine("Element: {0}", DirectCast(node, XElement).Name)
        Case XmlNodeType.Text
            Console.WriteLine("Text: {0}", DirectCast(node, XText).Value)
        Case XmlNodeType.Comment
            Console.WriteLine("Comment: {0}", DirectCast(node, XComment).Value)
        Case XmlNodeType.ProcessingInstruction
            Console.WriteLine("PI: {0}", DirectCast(node, XProcessingInstruction).Data)
    End Select
Next

This example produces the following output:

Text: aaa
Element: GrandChild
Text: Text
Comment: a comment
PI: type='text/xsl' href='test.xsl'
Text: ccc
Element: GrandChild
Text: Text
Text: ddd

The following is the same example, but in this case the XML is in a namespace. For more information, see Work with XML Namespaces.

XNamespace aw = "http://www.adventure-works.com";
XElement xmlTree = XElement.Parse(
@"
    aaaText
        
        
    
    cccTextddd
");
IEnumerable nodes =
    from node in xmlTree.Elements(aw + "Child").DescendantNodes()
    select node;

foreach (XNode node in nodes)
{
    switch (node.NodeType)
    {
        case XmlNodeType.Element:
            Console.WriteLine("Element: {0}", ((XElement)node).Name);
            break;
        case XmlNodeType.Text:
            Console.WriteLine("Text: {0}", ((XText)node).Value);
            break;
        case XmlNodeType.Comment:
            Console.WriteLine("Comment: {0}", ((XComment)node).Value);
            break;
        case XmlNodeType.ProcessingInstruction:
            Console.WriteLine("PI: {0}", ((XProcessingInstruction)node).Data);
            break;
    }
}

Imports 

Module Module1
    Sub Main()
        Dim xmlTree As XElement = _
        
            aaaText
                
                
            
            cccTextddd
        

        Dim nodes As IEnumerable(Of XNode) = _
            From node In xmlTree..DescendantNodes _
            Select node

        For Each node As XNode In nodes
            Select Case node.NodeType
                Case XmlNodeType.Element
                    Console.WriteLine("Element: {0}", DirectCast(node, XElement).Name)
                Case XmlNodeType.Text
                    Console.WriteLine("Text: {0}", DirectCast(node, XText).Value)
                Case XmlNodeType.Comment
                    Console.WriteLine("Comment: {0}", DirectCast(node, XComment).Value)
                Case XmlNodeType.ProcessingInstruction
                    Console.WriteLine("PI: {0}", DirectCast(node, XProcessingInstruction).Data)
            End Select
        Next
    End Sub
End Module

This example produces the following output:

Text: aaa
Element: {http://www.adventure-works.com}GrandChild
Text: Text
Comment: a comment
PI: type='text/xsl' href='test.xsl'
Text: ccc
Element: {http://www.adventure-works.com}GrandChild
Text: Text
Text: ddd

Remarks

This axis extension method is used on XDocument and XElement objects. Both of these types derive from XContainer, so this method operates on an IEnumerable of XContainer that contains the source collection.

Although Visual Basic has an integrated XML axis for descendant elements, there is no integrated axis for descendant nodes, so Visual Basic users must use this axis method explicitly.

This method uses deferred execution.

Applies to

See also