firebase - Flutter:向用户显示总分/等级

Question

我在状态中设置了 score、topicTotal 和 level，我正在打印它们中的每一个。 topicTotal 是所有分数相加的最终分数，level 基于它们的 topicTotal。

score 来自每个问题的 Firebase。我想根据 score 的总和计算总分，并根据总分向用户显示一个级别。

尽管我能够打印score、topicTotal 和level，但我无法向用户显示这些值。

我如何向用户显示这些值，如果我不能从状态中显示它们，我如何使用不同的方法检索和显示它们？

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

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

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

  set progress(double newValue) {
    _progress = newValue;
    notifyListeners();
  }

  set selected(Options newValue) {
    _selected = newValue;
    notifyListeners();
  }

  set score(dynamic newValue) {
    var score = idx += newValue.score;
    _score = newValue;
    print(score);
    _score = newValue;
    notifyListeners();
  }

  set topicTotal(dynamic newValue) {
    var topicTotal = idx;
    print(topicTotal);
    if (topicTotal <= 300) {
      print('Level 1');
    } else if (topicTotal <= 900) {
      print('Level 2');
    } else if (topicTotal <= 1400) {
      print('Level 3');
    } else
      print('Level 4');
    notifyListeners();
  }

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

  @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 level for the ${assessment.title} Assessment is ${state.topicTotal}',

Answer 1

您可以使用构建器方法像这样

StreamBuilder<QuerySnapshot>(
 stream: Firestore.instance.collection('DriverList').snapshots(),
 builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
   if (!snapshot.hasData) return new Text('Loading...');
   return new ListView(
      children: snapshot.data.documents.map((DocumentSnapshot document) {
         return new ListTile(
            title: new Text(document['name']),
            subtitle: new Text(document['phone']),
         );
      }).toList(),
   );
  },
);