LookupPrefix Method

XmlWriter.LookupPrefix Method

When overridden in a derived class, returns the closest prefix defined in the current namespace scope for the namespace URI.

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

'Declaration
Public MustOverride Function LookupPrefix ( _
	ns As String _
) As String

Parameters

ns
Type: System.String
The namespace URI whose prefix you want to find.

Return Value

Type: System.String
The matching prefix or Nothing if no matching namespace URI is found in the current scope.

ExceptionCondition
ArgumentException

ns is either Nothing or String.Empty.


Dim output As New StringBuilder()

Dim settings As New XmlWriterSettings()
settings.Indent = True
Using writer = XmlWriter.Create(output, settings)
    writer.WriteComment("sample XML fragment")

    ' Write an element (this one is the root).
    writer.WriteStartElement("book")

    ' Write the namespace declaration.
    writer.WriteAttributeString("xmlns", "bk", Nothing, "urn:samples")

    ' Write the genre attribute.
    writer.WriteAttributeString("genre", "novel")

    ' Write the title.
    writer.WriteStartElement("title")
    writer.WriteString("The Handmaid's Tale")
    writer.WriteEndElement()

    ' Write the price.
    writer.WriteElementString("price", "19.95")

    ' Lookup the prefix and write the ISBN element.
    Dim prefix As String = writer.LookupPrefix("urn:samples")
    writer.WriteStartElement(prefix, "ISBN", "urn:samples")
    writer.WriteString("1-861003-78")
    writer.WriteEndElement()

    ' Write the style element (shows a different way to handle prefixes).
    writer.WriteElementString("style", "urn:samples", "hardcover")

    ' Write the close tag for the root element.
    writer.WriteEndElement()

    ' Write the XML to file.
    writer.Flush()
End Using

OutputTextBlock.Text = output.ToString()


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

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

Community Additions

ADD
Show:
© 2016 Microsoft