Indeed, in order to apply a custom CSS class to the rendered li
HTML element of the RadRotator, you should utilize the Client API
of the control. I have attached a sample project, implementing the suggested solution. Note that I have set the index of the modified item statically and in your actual project you will have to get it from the code behind, which can be achieved via hidden field for example.
Please use the attached sample as a reference for your further development. Don't hesitate to contact us again if you encounter more difficulties.
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed