颤振：获得总分

Question

我的分数来自Firebase，基本上是在映射问题时，当前问题的分数会添加到先前问题的分数中，因此在最后一个问题上，您将从同一问题中获得最终分数分数变量，它们是所有彼此相加的分数。

我的问题是，我如何才能实际获得最终分数（最后一个问题的score变量的结果）并将其保存在totalScore变量中，以便我可以打印topicTotal？

class AssessmentState with ChangeNotifier {
  double _progress = 0;
  Options _selected;
  Options _score;
  Options _topicTotal;

  final PageController controller = PageController();
  var idx = 0;

  get progress => _progress;
  get selected => _selected;
  get score => _score;
  get topicTotal => _topicTotal;

// calculates the score
  set score(Options newValue) {
    var score = idx += newValue.score; 
    var finalScore = score;
    _score = newValue;              
    print(score);
    _score = newValue;  
    notifyListeners();
  }
  
//calculates the total score
  set topicTotal(Options newValue) {
    

    print(topicTotal);
    notifyListeners();
  }

class WellDonePage extends StatelessWidget {
  final Assessment assessment;
  final Questions questions;
  final Options options;
  WellDonePage({this.assessment, this.questions, this.options});

  @override
  Widget build(BuildContext context) {
    var state = Provider.of<AssessmentState>(context);

    return Padding(
      padding: EdgeInsets.all(20),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Text(
            'Well Done! You completed the ${assessment.title} Assessment. Your score of has been stored in your carbon footprint bucket.',
            style: greySubTxt,
            textAlign: TextAlign.center,
          ),
          SizedBox(height: 40),
          Image.asset('assets/well_done.gif'),
          Divider(),
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 40, horizontal: 20),
            child: FlatButton.icon(
                color: lightGrey,
                icon: Icon(FontAwesomeIcons.check, color: deepGrey),
                label: Text(' Mark Complete!', style: greyHead2Txt),
                onPressed: () {
                  
                 // PRINT THE TOPIC TOTAL SCORE HERE