XsltArgumentList.AddExtensionObject Method (String, Object)


Adds a new object to the XsltArgumentList and associates it with the namespace URI.

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

public void AddExtensionObject(
	string namespaceUri,
	object extension


Type: System.String

The namespace URI to associate with the object. To use the default namespace, specify an empty string.

Type: System.Object

The object to add to the list.

Exception Condition

The namespaceUri is either null or http://www.w3.org/1999/XSL/Transform

The namespaceUri already has an extension object associated with it.


The caller does not have sufficient permissions to call this method.

The params keyword, which allows an unspecified number of parameters to be passed, is currently not supported. XSLT style sheets that utilize methods defined with the params keyword does not work correctly. For more information, see params (C# Reference).

In the following example, the style sheet uses an XSLT extension object to convert the book price.

using System;
using System.IO;
using System.Xml;
using System.Xml.XPath;
using System.Xml.Xsl;

public class Sample {

   public static void Main() {

    // Create the XslCompiledTransform and load the stylesheet.
    XslCompiledTransform xslt = new XslCompiledTransform();

    // Create an XsltArgumentList.
    XsltArgumentList xslArg = new XsltArgumentList();

    // Add an object to calculate the new book price.
    BookPrice obj = new BookPrice();
    xslArg.AddExtensionObject("urn:price-conv", obj);

    using (XmlWriter w = XmlWriter.Create("output.xml"))
        // Transform the file.
        xslt.Transform("books.xml", xslArg, w);

  // Convert the book price to a new price using the conversion factor.
  public class BookPrice{

    private decimal newprice = 0;

    public decimal NewPriceFunc(decimal price, decimal conv){
       decimal tmp = price*conv;
       newprice = decimal.Round(tmp, 2);
       return newprice;

The example uses the following data files as input.


  <book genre="autobiography" publicationdate="1981" ISBN="1-861003-11-0">
    <title>The Autobiography of Benjamin Franklin</title>
  <book genre="novel" publicationdate="1967" ISBN="0-201-63361-2">
    <title>The Confidence Man</title>
  <book genre="philosophy" publicationdate="1991" ISBN="1-861001-57-6">
    <title>The Gorgias</title>


<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:myObj="urn:price-conv">

<!--Price conversion factor-->
<xsl:param name="conv" select="1.15"/>

  <xsl:template match="bookstore">
  <xsl:for-each select="book">
    <xsl:copy-of select="node()"/>
          <xsl:value-of select="myObj:NewPriceFunc(./price, $conv)"/>        

.NET Framework
Available since 1.1
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