Assembly: System.Web (in System.Web.dll)
Adding styles or style rules programmatically during asynchronous postbacks is not supported. When you add AJAX capabilities to an ASP.NET Web page, asynchronous postbacks update regions of the page without updating the whole page. For more information, see Microsoft Ajax Overview.
The following example shows how to programmatically add an embedded style rule for the HTML body element. This example is part of a larger example provided for the HtmlHead class.
Available since 2.0