Flutter操纵上部小部件的数据

Question

我是Flutter的新手。我尝试适应提供者。我有一个QuestionsScreen小部件，它是用FutureBuilder构建的，并且我将QuestionItem用作项目生成器。我的visible类具有AssessmentQuestion属性，某些问题的选项可能会触发特定问题对该属性的更改。那么如何更改QuestionItem上方列表中的属性？

我尝试使用Provider.of，但不确定是否是这种方式。

// QuestionsScreen - builder

class QuestionsScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final QuestionsScreenArguments args = ModalRoute.of(context).settings.arguments;
    return ChangeNotifierProvider(
      builder: (_) => QuestionsState(),
      child: FutureBuilder(
        future: DbService.getAssessment(args.assessment.id),
        builder: (BuildContext context, AsyncSnapshot snap) {
          var state = Provider.of<QuestionsState>(context);

          if (snap.hasData) {
            List<AssessmentQuestion> questions = snap.data;
            return Scaffold(
              appBar: AppBar(
                backgroundColor: Colors.deepPurple,
                title: Text(args.assessment.name),
                actions: [
                  IconButton(
                    icon: Icon(FontAwesomeIcons.listAlt,
                        color: Colors.pink[200]),
                    onPressed: () => Navigator.pushNamed(context, '/assessments'),
                  )
                ],
              ),
              body: GridView.count(
                primary: false,
                padding: const EdgeInsets.all(20.0),
                crossAxisSpacing: 10.0,
                crossAxisCount: 1,
                children: questions.map((question) => QuestionItem(question: question)).toList(),
              ),
            );
          } else {
            return LoadingScreen();
          }
        },
      ),
    );
  }
}

// Question Item -- here I want to achive dynamic change of visible or not
class QuestionItem extends StatelessWidget {
  final AssessmentQuestion question;
  QuestionItem({this.question});

  @override
  Widget build(BuildContext context) {
    var state = Provider.of<QuestionsState>(context);
    if (question.visible) {
      return Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          Container(
            padding: EdgeInsets.all(10),
            alignment: Alignment.center,
            child: Text(question.order.toString() + ') ' + question.text),
          ),
          Container(
            padding: EdgeInsets.all(12),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: question.options.map((opt) {
                return Container(
                  height: 90,
                  margin: EdgeInsets.only(bottom: 10),
                  color: Colors.black26,
                  child: InkWell(
                    onTap: () {
                      state.selected(opt);
                    },
                    child: Container(
                      padding: EdgeInsets.all(16),
                      child: Row(
                        children: [
                          Icon(
                              state.selectedOptions.contains(opt)
                                  ? FontAwesomeIcons.checkCircle
                                  : FontAwesomeIcons.circle,
                              size: 30, 
                              color: state.selectedOptions.contains(opt) ? Colors.orange : Colors.grey),
                          Expanded(
                            child: Container(
                              margin: EdgeInsets.only(left: 16),
                              child: Text(
                                opt.text,
                              ),
                            ),
                          ),

                        ],
                      ),
                    ),
                  ),
                );
              }).toList(),
            ),
          )
        ],
      );
    } else {
      return Column(
        children: <Widget>[
          Text('Not visible'),
        ],
      );
    }
  }
}

// On option select this is called
void selected(Option newValue) {
    List<dynamic> toRemove = [];
    String questionType = newValue.question.type;
    if (selectedOptions.contains(newValue)) {
      toRemove.add(newValue);
    } else {
      switch(questionType) {
        case 'singleChoice':
          selectedOptions.forEach((opt) {
            if (opt is Option && opt.question == newValue.question) {
              toRemove.add(opt);
            }
          });
          selectedOptions.add(newValue);
          break;
        case 'multipleChoice':
          selectedOptions.add(newValue);
        break;
        default:
        break;
      }

      if (newValue.question != null) {
        newValue.question.visible = true;
      }
    }
    selectedOptions.removeWhere((e) => toRemove.contains(e));
    notifyListeners();
  }
}

我希望在QuestionItem中单击某个选项时显示相关问题。