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IXmlNamespaceResolver.LookupPrefix Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Gets the prefix that is mapped to the specified namespace URI.

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

Syntax

'Declaration
Function LookupPrefix ( _
    namespaceName As String _
) As String

string LookupPrefix(
    string namespaceName
)

Parameters

  • namespaceName
    Type: System.String
    The namespace URI whose prefix you wish to find.

Return Value

Type: System.String
The prefix that is mapped to the namespace URI; nulla null reference (Nothing in Visual Basic) if the namespace URI is not mapped to a prefix.

Remarks

It is possible for a namespace URI to be mapped to multiple prefixes. Because the prefixes are not mapped in a predictable manner, you should not depend on getting back a particular prefix when a namespace URI is mapped to more than one prefix.

NoteNote:

Namespace URI to prefix mappings can change from node to node in an XML document. You cannot depend on the result of a lookup being consistent from one node to the next.

The following table describes how the default and built-in namespaces are handled by the LookupPrefix method.

Namespace

Return value

http://www.w3.org/XML/1998/namespace

xml

http://www.w3.org/2000/xmlns/

xmlns

An empty namespace.

A default namespace that has not been defined.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.