当我回来或结束时如何重置我的控制器？

Question

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我有一个 QuestionController 类扩展GetxController

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当我使用控件退出页面时，我希望它停止工作（因为它仍在后台运行），并在我返回该页面时重新启动。

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ScoreScreen()我已经尝试过：我在(in )的路线之后添加了这些nextQuestion ()：

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_isAnswered = false;\n_questionNumber.value = 1; \n

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在进入分数页面之前，我重置了值 \xe2\x80\x8b\xe2\x80\x8b。如果您进入乐谱页面，它可能会起作用，但如果您早点回来，它就不会起作用。（上面的问题 num/4 在这里不起作用）。所以这种方式不适合。

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页面退出时如何停止并重置它？

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控制器类代码：

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class QuestionController extends GetxController\n    with SingleGetTickerProviderMixin {\n  PageController _pageController;\n\n  PageController get pageController => this._pageController;\n\n  List<Question> _questions = questions_data\n      .map(\n        (e) => Question(\n            id: e["id"],\n            question: e["question"],\n            options: e["options"],\n            answer: e["answer_index"]),\n      )\n      .toList();\n\n  List<Question> get questions => this._questions;\n\n  bool _isAnswered = false;\n\n  bool get isAnswered => this._isAnswered;\n\n  int _correctAns;\n\n  int get correctAns => this._correctAns;\n\n  int _selectedAns;\n\n  int get selectedAns => this._selectedAns;\n\n  RxInt _questionNumber = 1.obs;\n\n  RxInt get questionNumber => this._questionNumber;\n\n  int _numOfCorrectAns = 0;\n\n  int get numOfCorrectAns => this._numOfCorrectAns;\n\n  @override\n  void onInit() {\n    _pageController = PageController();\n    super.onInit();\n  }\n\n  @override\n  void onClose() {\n    super.onClose();\n    _pageController.dispose();\n  }\n\n  void checkAns(Question question, int selectedIndex) {\n    _isAnswered = true;\n    _correctAns = question.answer;\n    _selectedAns = selectedIndex;\n\n    if (_correctAns == _selectedAns) _numOfCorrectAns++;\n\n    update();\n\n    Future.delayed(Duration(seconds: 2), () {\n      nextQuestion();\n    });\n  }\n\n  void nextQuestion() {\n    if (_questionNumber.value != _questions.length) {\n      _isAnswered = false;\n      _pageController.nextPage(\n          duration: Duration(milliseconds: 300), curve: Curves.ease);\n    } else {\n      Get.off(ScoreScreen(correctNum: _numOfCorrectAns)); // GetMaterialApp()\n\n      // _isAnswered = false;\n\n      _numOfCorrectAns = 0;\n\n      //_questionNumber.value = 1;\n\n    }\n  }\n\n  void updateTheQuestionNum(int index) {\n    _questionNumber.value = index + 1;\n  }\n}\n

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完整代码如下

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import \'package:flutter/material.dart\';\nimport \'dart:async\';\nimport \'package:get/get.dart\';  // get: ^3.25.4\n\n//  QuizPage()     ===============> 50. line      (Question 1/4) 81. line\n//  QuestionCard()  ==============> 116. line\n//  Option()   ===================> 163. line\n//  QuestionController()  ========> 218. line\n//  ScoreScreen() ================> 345. line\n\nvoid main() => runApp(new MyApp());\n\nclass MyApp extends StatelessWidget {\n  @override\n  Widget build(BuildContext context) {\n    return GetMaterialApp(\n      debugShowCheckedModeBanner: false,\n      theme: ThemeData(canvasColor: Colors.blue),\n      home: HomeScreen(),\n    );\n  }\n}\n\nclass HomeScreen extends StatelessWidget {\n  @override\n  Widget build(BuildContext context) {\n    return Scaffold(\n      appBar: AppBar(\n        title: Text("Home Page"),\n      ),\n      body: Center(\n        child: InkWell(\n          onTap: () {\n            Navigator.push(\n                context, MaterialPageRoute(builder: (context) => QuizPage()));\n          },\n          child: Container(\n            padding: EdgeInsets.all(22),\n            color: Colors.green,\n            child: Text(\n              "Go Quiz Page",\n              style: TextStyle(color: Colors.white),\n            ),\n          ),\n        ),\n      ),\n    );\n  }\n}\n\nclass QuizPage extends StatelessWidget {\n  const QuizPage({\n    Key key,\n  }) : super(key: key);\n\n  @override\n  Widget build(BuildContext context) {\n    QuestionController _questionController = Get.put(QuestionController());\n\n    return Scaffold(\n      appBar: AppBar(\n        title: Text("Quiz Page"),\n      ),\n      body: Stack(\n        children: [\n          SafeArea(\n            child: Column(\n              crossAxisAlignment: CrossAxisAlignment.start,\n              children: [\n                SizedBox(\n                  height: 16,\n                ),\n                Padding(\n                  padding: EdgeInsets.symmetric(horizontal: 16),\n                  child: Obx(\n                    () => Center(\n                      child: RichText(\n                          text: TextSpan(\n                              // text,style default adjust here OR:children[TextSpan(1,adjust 1),TextSpan(2,adjust 2),..]\n                              text:\n                                  "Question ${_questionController._questionNumber.value}",\n                              style: TextStyle(\n                                  fontSize: 33, color: Colors.white70),\n                              children: [\n                            TextSpan(\n                                text:\n                                    "/${_questionController._questions.length}",\n                                style: TextStyle(fontSize: 25))\n                          ])),\n                    ),\n                  ),\n                ),\n                Divider(color: Colors.white70, thickness: 1),\n                SizedBox(\n                  height: 16,\n                ),\n                Expanded(\n                  child: PageView.builder(\n                    physics: NeverScrollableScrollPhysics(),\n                    controller: _questionController._pageController,\n                    onPageChanged: _questionController.updateTheQuestionNum,\n                    itemCount: _questionController.questions.length,\n                    itemBuilder: (context, index) => QuestionCard(\n                      question: _questionController.questions[index],\n                    ),\n                  ),\n                )\n              ],\n            ),\n          )\n        ],\n      ),\n    );\n  }\n}\n\nclass QuestionCard extends StatelessWidget {\n  final Question question;\n\n  const QuestionCard({\n    Key key,\n    @required this.question,\n  }) : super(key: key);\n\n  @override\n  Widget build(BuildContext context) {\n    QuestionController _controller = Get.put(QuestionController());\n\n    return Container(\n      margin: EdgeInsets.only(left: 16, right: 16, bottom: 16),\n      padding: EdgeInsets.all(16),\n      decoration: BoxDecoration(\n        borderRadius: BorderRadius.circular(25),\n        color: Colors.white,\n      ),\n      child: Column(\n        children: [\n          Text(\n            question.question,\n            style: TextStyle(fontSize: 22),\n          ),\n          SizedBox(\n            height: 8,\n          ),\n          Flexible(\n            child: SingleChildScrollView(\n              child: Column(\n                children: [\n                  ...List.generate(\n                      question.options.length,\n                      (index) => Option(\n                          text: question.options[index],\n                          index: index,\n                          press: () => _controller.checkAns(question, index)))\n                ],\n              ),\n            ),\n          )\n        ],\n      ),\n    );\n  }\n}\n\nclass Option extends StatelessWidget {\n  final String text;\n  final int index;\n  final VoidCallback press;\n\n  const Option({\n    Key key,\n    @required this.text,\n    @required this.index,\n    @required this.press,\n  }) : super(key: key);\n\n  @override\n  Widget build(BuildContext context) {\n    return GetBuilder<QuestionController>(\n        init: QuestionController(),\n        builder: (q) {\n          Color getRightColor() {\n            if (q.isAnswered) {\n              if (index == q._correctAns) {\n                return Colors.green;\n              } else if (index == q.selectedAns &&\n                  q.selectedAns != q.correctAns) {\n                return Colors.red;\n              }\n            }\n            return Colors.blue;\n          }\n\n          return InkWell(\n            onTap: press,\n            child: Container(\n              //-- Option\n              margin: EdgeInsets.only(top: 16),\n              padding: EdgeInsets.all(16),\n              decoration: BoxDecoration(\n                  color: getRightColor(),\n                  borderRadius: BorderRadius.circular(16)),\n              child: Row(\n                mainAxisAlignment: MainAxisAlignment.spaceBetween,\n                children: [\n                  Text(\n                    "${index + 1}. $text",\n                    style: TextStyle(fontSize: 16, color: Colors.white),\n                  ),\n                ],\n              ),\n            ),\n          );\n        });\n  }\n}\n\nclass QuestionController extends GetxController\n    with SingleGetTickerProviderMixin {\n  PageController _pageController;\n\n  PageController get pageController => this._pageController;\n\n  List<Question> _questions = questions_data\n      .map(\n        (e) => Question(\n            id: e["id"],\n            question: e["question"],\n            options: e["options"],\n            answer: e["answer_index"]),\n      )\n      .toList();\n\n  List<Question> get questions => this._questions;\n\n  bool _isAnswered = false;\n\n  bool get isAnswered => this._isAnswered;\n\n  int _correctAns;\n\n  int get correctAns => this._correctAns;\n\n  int _selectedAns;\n\n  int get selectedAns => this._selectedAns;\n\n  RxInt _questionNumber = 1.obs;\n\n  RxInt get questionNumber => this._questionNumber;\n\n  int _numOfCorrectAns = 0;\n\n  int get numOfCorrectAns => this._numOfCorrectAns;\n\n  @override\n  void onInit() {\n    _pageController = PageController();\n    //_pageController.addListener(() { _questionNumber.value = _pageController.page.round()+1; });\n    super.onInit();\n  }\n\n  @override\n  void onClose() {\n    super.onClose();\n    _pageController.dispose();\n  }\n\n  void checkAns(Question question, int selectedIndex) {\n    _isAnswered = true;\n    _correctAns = question.answer;\n    _selectedAns = selectedIndex;\n\n    if (_correctAns == _selectedAns) _numOfCorrectAns++;\n\n    update();\n\n    Future.delayed(Duration(seconds: 2), () {\n      nextQuestion();\n    });\n  }\n\n  void nextQuestion() {\n    if (_questionNumber.value != _questions.length) {\n      _isAnswered = false;\n      _pageController.nextPage(\n          duration: Duration(milliseconds: 300), curve: Curves.ease);\n    } else {\n      Get.off(ScoreScreen(correctNum: _numOfCorrectAns)); // GetMaterialApp()\n\n      // _isAnswered = false;\n\n      _numOfCorrectAns = 0;\n\n      //_questionNumber.value = 1;\n\n    }\n  }\n\n  void updateTheQuestionNum(int index) {\n    _questionNumber.value = index + 1;\n  }\n}\n\nclass Question {\n  final int id, answer;\n  final String question;\n  final List<String> options;\n\n  Question({\n    @required this.id,\n    @required this.question,\n    @required this.options,\n    @required this.answer,\n  });\n}\n\nconst List questions_data = [\n  {\n    "id": 1,\n    "question": "Question 1",\n    "options": [\'option A\', \'B\', \'C\', \'D\'],\n    "answer_index": 3,\n  },\n  {\n    "id": 2,\n    "question": "Question 2",\n    "options": [\'option A\', \'B\', \'C\', \'D\'],\n    "answer_index": 2,\n  },\n  {\n    "id": 3,\n    "question": "Question 3",\n    "options": [\'option A\', \'B\', \'C\', \'D\'],\n    "answer_index": 0,\n  },\n  {\n    "id": 4,\n    "question": "Question 4",\n    "options": [\'option A\', \'B\', \'C\', \'D\'],\n    "answer_index": 0,\n  },\n];\n\nclass ScoreScreen extends StatelessWidget {\n  final int correctNum;\n\n  ScoreScreen({@required this.correctNum});\n\n  @override\n  Widget build(BuildContext context) {\n    QuestionController _qController = Get.put(QuestionController());\n\n    return Scaffold(\n      body: Stack(\n        fit: StackFit.expand,\n        children: [\n          Column(\n            children: [\n              Spacer(\n                flex: 2,\n              ),\n              Text(\n                "Score",\n                style: TextStyle(fontSize: 55, color: Colors.white),\n              ),\n              Spacer(),\n              Text(\n                "${correctNum * 10}/${_qController.questions.length * 10}",\n                style: TextStyle(fontSize: 33, color: Colors.white),\n              ),\n              Spacer(\n                flex: 2,\n              ),\n              InkWell(\n                onTap: () => Get.back(),\n                borderRadius: BorderRadius.circular(16),\n                child: Container(\n                  padding: EdgeInsets.all(16),\n                  decoration: BoxDecoration(\n                      borderRadius: BorderRadius.circular(16),\n                      color: Colors.white24),\n                  child: Text(\n                    "Back to Home Page",\n                    style: TextStyle(color: Colors.white),\n                  ),\n                ),\n              ),\n              Spacer(),\n            ],\n          ),\n        ],\n      ),\n    );\n  }\n}\n

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Answer 1

如果您只想重置一个控制器，那么您可以使用Get.delete<ExecutableController>();

用于重置所有控制器Get.deleteAll();