XmlReader.LookupNamespace(String) Method

Definition

Namespace:

System.Xml

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlReader.cs

When overridden in a derived class, resolves a namespace prefix in the current element's scope.

public:
 abstract System::String ^ LookupNamespace(System::String ^ prefix);

public abstract string? LookupNamespace (string prefix);

abstract member LookupNamespace : string -> string

Public MustOverride Function LookupNamespace (prefix As String) As String

Parameters

prefix

String

The prefix whose namespace URI you want to resolve. To match the default namespace, pass an empty string.

Returns

String

The namespace URI to which the prefix maps or null if no matching prefix is found.

Exceptions

InvalidOperationException

An XmlReader method was called before a previous asynchronous operation finished. In this case, InvalidOperationException is thrown with the message "An asynchronous operation is already in progress."

Remarks

In the following XML string, 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>