Occurs when the core Silverlight rendering process renders a frame.
(in System.Windows.dll)
Visual Basic (Declaration)
Public Shared Event Rendering As EventHandler
Dim handler As EventHandler
AddHandler CompositionTarget.Rendering, handler
public static event EventHandler Rendering
Use the general EventHandler delegate for this event. Rendering uses the EventHandler delegate and EventArgs event data by its strict signature. However, you can base a handler on EventHandler and then cast the event data to RenderingEventArgs. Then you can get the RenderingTime property value for that occurrence of the event.
When the event occurs, it means that there is a frame of visuals available to render to the Silverlight content surface. You can then modify the visuals or any other aspect of your application on a per-frame basis within your handler.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
Reference