This method is intended for use by control developers who want to extend the UpdatePanel control. For example, in derived classes, you can provide a different root control that acts as a container for your UpdatePanel control's content. The default implementation returns a Control object.
The following example shows how to override the CreateContentTemplateContainer method in a custom UpdatePanel control to always render the <fieldset> and <legend> elements for the panel's content. The custom UpdatePanel control defines a public property named GroupingText that is a string literal inside the <legend> element.
A custom UpdatePanel control named CustomUpdatePanel derives from UpdatePanel and overrides the CreateContentTemplateContainer method. Put the CustomUpdatePanel class source code in the Web site's App_Code folder.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)