This event is fired by the animation tool just before a screenshot is captured.
[Visual Basic .NET] Public Sub ReadyToSnap ( _ ByVal vTimeStamp As Object, _ ByVal nFrameNum As Integer _ )
[C#] public void ReadyToSnap ( object vTimeStamp, int nFrameNum );
Product Availability
Available with ArcGIS Desktop. Requires Tracking Analyst Extension.