protected unsafe void EnableActionSourceType()
        {
            iCallbackSourceType = new CallbackSourceType(DoSourceType);
            IntPtr ptr = GCHandle.ToIntPtr(iGch);

            DvServiceLinnCoUkProduct3EnableActionSourceType(iHandle, iCallbackSourceType, ptr);
        }
 static extern void DvServiceLinnCoUkProduct3EnableActionSourceType(uint aHandle, CallbackSourceType aCallback, IntPtr aPtr);