XmlNode.SelectSingleNode Method


Selects the first XmlNode that matches the XPath expression.

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


Selects the first XmlNode that matches the XPath expression.

System_CAPS_pubmethodSelectSingleNode(String, XmlNamespaceManager)

Selects the first XmlNode that matches the XPath expression. Any prefixes found in the XPath expression are resolved using the supplied XmlNamespaceManager.

XPath expressions can include namespaces. Namespace resolution is supported using the XmlNamespaceManager. If the XPath expression includes a prefix, the prefix and namespace URI pair must be added to the XmlNamespaceManager.


If the XPath expression does not include a prefix, it is assumed that the namespace URI is the empty namespace. If your XML includes a default namespace, you must still add a prefix and namespace URI to the XmlNamespaceManager; otherwise, you will not get any nodes selected. For more information, see Select Nodes Using XPath Navigation.

The following example returns the first book with the matching author name. The XmlNamespaceManager resolves the default namespace in the XPath expression.

Imports System
Imports System.IO
Imports System.Xml

Public Class Sample

  Public Shared Sub Main()

      Dim doc As XmlDocument = New XmlDocument()

      'Create an XmlNamespaceManager for resolving namespaces.
      Dim nsmgr As XmlNamespaceManager = New XmlNamespaceManager(doc.NameTable)
      nsmgr.AddNamespace("bk", "urn:newbooks-schema")

      'Select the book written by an author whose last name is Atwood.
      Dim book As XmlNode 
      Dim root As XmlElement = doc.DocumentElement
      book = root.SelectSingleNode("descendant::bk:book[bk:author/bk:last-name='Atwood']", nsmgr)


  End Sub
End Class

The example uses the file, newbooks.xml, as input.

<?xml version='1.0'?>
<bookstore xmlns="urn:newbooks-schema">
  <book genre="novel" style="hardcover">
    <title>The Handmaid's Tale</title>
  <book genre="novel" style="other">
    <title>The Poisonwood Bible</title>
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