protected unsafe void EnableActionSeek()
        {
            iCallbackSeek = new CallbackSeek(DoSeek);
            IntPtr ptr = GCHandle.ToIntPtr(iGch);

            DvServiceUpnpOrgAVTransport2EnableActionSeek(iHandle, iCallbackSeek, ptr);
        }
 static extern void DvServiceUpnpOrgAVTransport2EnableActionSeek(uint aHandle, CallbackSeek aCallback, IntPtr aPtr);