Assembly: System.Web (in system.web.dll)
A lookup key with which to search for a SiteMapNode.
Return ValueA SiteMapNode that represents the page identified by key; otherwise, a null reference (Nothing in Visual Basic), if security trimming is enabled and the node cannot be shown to the current user or the node is not found by key in the node collection.
A child provider linked to the current site map provider returned a node that is not valid.
The XmlSiteMapProvider class overrides the FindSiteMapNodeFromKey method to ensure that any linked child providers are searched for the node, if the implementation for the base class does not return a node for key.
The XmlSiteMapProvider object, derived from the StaticSiteMapProvider class and the default site map provider for ASP.NET, uses the Url property of a SiteMapNode object as a lookup key in its internal collections, by default. If the Url property of the SiteMapNode is set, it must be unique within the scope of the provider. If no Url is specified, the XmlSiteMapProvider automatically generates a Key to track the nodes.
The FindSiteMapNodeFromKey method might call the BuildSiteMap method on any child providers that are associated with the current provider. Therefore, the exceptions that are described in the BuildSiteMap method might be thrown.
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.