XmlTextReader.LookupNamespace Method (System.Xml)

LookupNamespace Method

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Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

XmlTextReader..::.LookupNamespace Method

Resolves a namespace prefix in the current element's scope.

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

Syntax

Visual Basic (Declaration)

Public Overrides Function LookupNamespace ( _
    prefix As String _
) As String

Visual Basic (Usage)

Dim instance As XmlTextReader
Dim prefix As String
Dim returnValue As String

returnValue = instance.LookupNamespace(prefix)

public override string LookupNamespace(
    string prefix
)

Visual C++

public:
virtual String^ LookupNamespace(
    String^ prefix
) override

JScript

public override function LookupNamespace(
    prefix : String
) : String

Parameters

prefix: Type: System..::.String
The prefix whose namespace URI you want to resolve. To match the default namespace, pass an empty string. This string does not have to be atomized.

Return Value

Type: System..::.String
The namespace URI to which the prefix maps or nullNothingnullptra null reference (Nothing in Visual Basic) if no matching prefix is found.

Exceptions

Exception	Condition
ArgumentNullException	The Namespaces property is set to true and the prefix value is nullNothingnullptra null reference (Nothing in Visual Basic).

Remarks

Note:
In the .NET Framework version 2.0 release, the recommended practice is to create XmlReader instances using the XmlReader..::.Create method. This allows you to take full advantage of the new features introduced in this release. For more information, see Creating XML Readers.

In the following XML, if the reader is positioned on the href attribute, the prefix a is resolved by calling reader.LookupNamespace("a"). The returned string is urn:456.

 <root xmlns:a="urn:456">
  <item>
  <ref href="a:b"/>
  </item>
 </root>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

Reference

XmlTextReader Class

XmlTextReader Members

System.Xml Namespace

Other Resources

Reading XML with the XmlReader