XPathMessageContext Class
Assembly: System.ServiceModel (in system.servicemodel.dll)
The XPath engine has full XPath context support and uses the .NET Framework's XsltContext class in the same way that XPathNavigator does to implement this support. XsltContext is an abstract class that allows developers to implement custom XPath function libraries and declare XPath variables. XsltContext is an XmlNamespaceManager and thus also contains the namespace prefix mappings.
The filter engine implements an XsltContext named XPathMessageContext. XPathMessageContext defines custom functions that can be used in XPath expressions and it declares several common namespace prefix mappings.
System.Xml.XmlNamespaceManager
System.Xml.Xsl.XsltContext
System.ServiceModel.Dispatcher.XPathMessageContext
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.