Occurs before the style sheet that is defined by the XmlDataSource.Transform property or identified by the XmlDataSource.TransformFile property is applied to XML data.
Handle the XmlDataSource.Transforming event to set the XmlDataSource.TransformArgumentList property with an System.Xml.Xsl.XsltArgumentList object before the System.Web.UI.WebControls.XmlDataSource control performs an XML transformation.
For more information about handling events, see [<topic://cpconEventsOverview>].