ReceivePort in Project Example is not working

[ixsans]

I'm trying to run project example. When i tried to log Geofencing callback, it's working. It's sending message from SendingPort but ReceivePort.listen() is not triggered. I want to modify some state inside this listen callback, but it's never called.

 IsolateNameServer.registerPortWithName(
        port.sendPort, 'geofencing_send_port');
    port.listen((dynamic data) {
      /// THIS CALLBACK NEVER TRIGGERED
      print('Event: $data');
      setState(() {
        geofenceState = data;
      });
    });

I'm unable to change state of my objects inside callback function as it's static function while my objects isn't static.