Extensions.XPathSelectElements Method (XNode, String, IXmlNamespaceResolver) (System.Xml.XPath)

MSDN Library
.NET Development
.NET Framework 3.5
.NET Framework Class Library
System.Xml.XPath Namespace
Extensions Class
Extensions Methods
XPathSelectElements Method

XPathSelectElements Method (XNode, String)

XPathSelectElements Method (XNode, String, IXmlNamespaceResolver)

Related Links

Extensions Members
Extensions Methods

Extensions..::.XPathSelectElements Method (XNode, String, IXmlNamespaceResolver)
This page is specific to:.NET Framework Version:3.54.0

.NET Framework Class Library

Extensions..::.XPathSelectElements Method (XNode, String, IXmlNamespaceResolver)

Selects a collection of elements using an XPath expression, resolving namespace prefixes using the specified IXmlNamespaceResolver.

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

Syntax

C++

JScript

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'Usage

Dim node As XNode
Dim expression As String
Dim resolver As IXmlNamespaceResolver
Dim returnValue As IEnumerable(Of XElement)

returnValue = node.XPathSelectElements(expression, _
    resolver)

'Declaration

<ExtensionAttribute> _
Public Shared Function XPathSelectElements ( _
    node As XNode, _
    expression As String, _
    resolver As IXmlNamespaceResolver _
) As IEnumerable(Of XElement)

Parameters

node: Type: System.Xml.Linq..::.XNode
The XNode on which to evaluate the XPath expression.

expression: Type: System..::.String
A String that contains an XPath expression.

resolver: Type: System.Xml..::.IXmlNamespaceResolver
A IXmlNamespaceResolver for the namespace prefixes in the XPath expression.

Return Value

Type: System.Collections.Generic..::.IEnumerable<(Of <(XElement>)>)
An IEnumerable<(Of <(T>)>) of XElement that contains the selected elements.

Usage Note

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

Remarks

You can use this method to evaluate XPath expressions that contain namespace prefixes.

Although the ordering of returned collections is not specified in the XML XPath Language 1.0 Recommendation, this extension method returns nodes in document order.

Note that nodes are returned in document order even when you use a reverse axis, such as preceding-sibling or ancestor-or-self.

Examples

This example creates an XML tree that contains a namespace. It uses an XmlReader to read the XML document. It then gets an XmlNameTable from the XmlReader, and an XmlNamespaceManager from the XmlNameTable. It uses the XmlNamespaceManager when selecting the list of elements.

C++

JScript

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Dim markup As XElement = _
<aw:Root xmlns:aw="http://www.adventure-works.com">
    <aw:Child1>child one data 1</aw:Child1>
    <aw:Child1>child one data 2</aw:Child1>
    <aw:Child1>child one data 3</aw:Child1>
    <aw:Child2>child two data 4</aw:Child2>
    <aw:Child2>child two data 5</aw:Child2>
    <aw:Child2>child two data 6</aw:Child2>
</aw:Root>
Dim reader As XmlReader = markup.CreateReader
Dim nameTable As XmlNameTable = reader.NameTable
Dim namespaceManager As XmlNamespaceManager = New XmlNamespaceManager(nameTable)
namespaceManager.AddNamespace("aw", "http://www.adventure-works.com")
Dim elements As IEnumerable(Of XElement) = markup.XPathSelectElements("./aw:Child1", namespaceManager)
For Each el As XElement In elements
    Console.WriteLine(el)
Next

This example produces the following output:

<aw:Child1 xmlns:aw="http://www.adventure-works.com">child one data 1</aw:Child1>
<aw:Child1 xmlns:aw="http://www.adventure-works.com">child one data 2</aw:Child1>
<aw:Child1 xmlns:aw="http://www.adventure-works.com">child one data 3</aw:Child1>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

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

Version Information

.NET Framework

Supported in: 3.5

Reference

Extensions Class

Extensions Members

XPathSelectElements Overload

System.Xml.XPath Namespace