Raises the event.
Assembly: System.Web.Extensions (in System.Web.Extensions.dll)
The method is used by control developers to extend the functionality of the UpdatePanel control.
The method writes the rendered content of the UpdatePanel control to the browser by using the supplied HtmlTextWriter object. When you override the method in a derived class, make sure to call the method of the base class so that the child controls of the UpdatePanel control are rendered.