protected unsafe void EnableActionSourceVisible()
        {
            iCallbackSourceVisible = new CallbackSourceVisible(DoSourceVisible);
            IntPtr ptr = GCHandle.ToIntPtr(iGch);

            DvServiceLinnCoUkProduct3EnableActionSourceVisible(iHandle, iCallbackSourceVisible, ptr);
        }
 static extern void DvServiceLinnCoUkProduct3EnableActionSourceVisible(uint aHandle, CallbackSourceVisible aCallback, IntPtr aPtr);