Riverpod 不通知听众

问题描述

我正在编写一个测验应用程序来学习 riverpod，这里是我的提供者：

final questionProvider = Provider((ref) => shuffled(Statics.q).sublist(0,10)); // holding the List of questions (Exam consists of 10 questions)

final indexProvider = StateProvider((ref) => 0); // Holding the index of the question (0-9)

final questionStateProvider =
    StateNotifierProvider.autodispose<QStateNotifier,Question>((ref) {
  final _index = ref.watch(indexProvider).state; // Index of the question
  final _questions = ref.read(questionProvider); // List of questions
  return QStateNotifier(_questions[_index]);
});

这是我的用户界面的一部分。


class AnswerBar extends HookWidget { // This Widget shows the clicked letters(via CharPadButton)
  AnswerBar({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    var _question = useProvider(questionStateProvider);
    if (_question.answer.length == 2) {
      print(_question.hashCode);
      return Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,children: [
          AnswerBubble(char: _question.answerBar[0]),// AnswerBubbles are where i show the clicked chars that coming from CharPadButtons.
          AnswerBubble(char: _question.answerBar[1]),],);
    }

这是我获取所问问题的字符输入的按钮。

class CharPadButtons extends HookWidget { // Every CharPadButton has a Text Widget as a child which contains a letter.
  CharPadButtons({Key? key,required this.char}) : super(key: key);
  final String char;
  bool isTapped = false;

  @override
  Widget build(BuildContext context) {
    final _questionNotifier = useProvider(questionStateProvider.notifier);
    return InkWell(
      onTap: () {
        if (isTapped == false) {
          _questionNotifier.addAnswerBar(char);

          isTapped = true;
        }
      },

这是我的 StateNotifier :

class QStateNotifier extends StateNotifier<Question> {
  QStateNotifier(Question state) : super(state);

  void addAnswerBar(String char) {
    var temp = [...state.answerBar];
    temp.insert(state.currentAnswerBarIndex,char);
    var tempCurrentBarIndex = state.currentAnswerBarIndex + 1;

    state = Question(
        description: state.description,answer: state.answer,answerBar: temp,currentAnswerBarIndex: tempCurrentBarIndex);
    print(state.answerBar); // I put it to see if answerBar is updated correctly and yes.
  }

问题模型：


class Question extends Equatable {
  final String description;
  final List<String> answer;
  final List<String> answerBar;
  final List<String> randomBar;
  final int currentAnswerBarIndex;

  Question({
    required this.description,required this.answer,this.answerBar = const ['','',''],this.currentAnswerBarIndex = 0,}) : randomBar = shuffleit([...answer,...randLetterChoice(answer.length)]);

  @override
  List<Object?> get props => [answerBar,currentAnswerBarIndex];
}

尽管 answerBar 正在正确更新自身，但不会重建 UI。StateNotifier 的状态（它是一个 Question 对象）在每次点击 CharPadButtons 小部件时更新。但是 _question.answerBar[index] 没有更新，我不明白为什么没有通知监听器并且没有重建 UI。

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。

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dart riverpod