从所有小部件获取所有分数

Question

我正在构建一个测验应用程序，我创建了一个自定义小部件来节省我很多时间，因为我有很多测验问题。除了评分系统之外，一切都有效。如果我创建同一个小部件的多个实例，分数将不会递增，它将保持在 1。有什么方法可以将小部件的每个分数传递到我的主小部件中的全局变量，这样我就可以添加所有分数？（我是新手）。

自定义小部件

class Questions extends StatefulWidget {
  final String imagePath;
  final String question;
  final String answer1;
  final String answer2;
  final String answer3;
  final String answer4;
  final bool iscorrectAnswer1;
  final bool iscorrectAnswer2;
  final bool iscorrectAnswer3;
  final bool iscorrectAnswer4;

  int score = 0;

  bool questionsAnswered = false;

  Questions(
    this.imagePath,
    this.question,
    this.answer1,
    this.answer2,
    this.answer3,
    this.answer4,
    this.iscorrectAnswer1,
    this.iscorrectAnswer2,
    this.iscorrectAnswer3,
    this.iscorrectAnswer4,
  );

  @override
  _QuestionsState createState() => _QuestionsState();
}

class _QuestionsState extends State<Questions> {
  disableButton() {
    setState(() {
      widget.questionsAnswered = true;
      Quiz().score += widget.score;
    });
  }

  @override
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        SizedBox(
          width: 600,
          height: 600,
          child: Image.asset(widget.imagePath),
        ),
        Align(
            alignment: Alignment.topCenter,
            child: Padding(
              padding: EdgeInsets.only(
                top: 20,
              ),
              child: Text(
                widget.question,
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 38,
                ),
              ),
            )),
        Padding(
            padding: EdgeInsets.only(
              top: 40,
            ),
            child: SizedBox(
              width: 500,
              height: 60,
              child: ClipRRect(
                borderRadius: BorderRadius.all(Radius.circular(15)),
                child: ElevatedButton(
                    style: ButtonStyle(
                      backgroundColor: MaterialStateProperty.all(
                        Color(0xFF304e60),
                      ),
                    ),
                    child: Text(
                      widget.answer1,
                      style: TextStyle(
                        color: Colors.white,
                        fontSize: 15,
                      ),
                    ),
                    onPressed: widget.questionsAnswered == false
                        ? () {
                            setState(() {
                              if (widget.iscorrectAnswer1 == true) {
                                ScaffoldMessenger.of(context).showSnackBar(
                                  SnackBar(
                                    content: Text('Correct!'),
                                  ),
                                );
                                disableButton();
                                widget.score += 1;
                              } else {
                                ScaffoldMessenger.of(context)
                                    .showSnackBar(SnackBar(
                                  content: Text('Wrong Answer!'),
                                ));
                              }
                            });
                            print(widget.iscorrectAnswer1);
                            print(widget.score);
                          }
                        : null),
              ),
            )),
        Padding(
            padding: EdgeInsets.only(
              top: 10,
            ),
            child: SizedBox(
              width: 500,
              height: 60,
              child: ClipRRect(
                borderRadius: BorderRadius.all(Radius.circular(15)),
                child: ElevatedButton(
                    style: ButtonStyle(
                        backgroundColor:
                            MaterialStateProperty.all(Color(0xFF565462))),
                    child: Text(
                      widget.answer2,
                      style: TextStyle(
                        color: Colors.white,
                        fontSize: 15,
                      ),
                    ),
                    onPressed: widget.questionsAnswered == false
                        ? () {
                            setState(() {
                              if (widget.iscorrectAnswer2 == true) {
                                ScaffoldMessenger.of(context).showSnackBar(
                                  SnackBar(
                                    content: Text('Correct!'),
                                  ),
                                );
                                widget.score += 1;
                              } else {
                                disableButton();
                                ScaffoldMessenger.of(context)
                                    .showSnackBar(SnackBar(
                                  content: Text('Wrong Answer!'),
                                ));
                              }
                            });
                          }
                        : null),
              ),
            )),
        Padding(
          padding: EdgeInsets.only(
            top: 10,
          ),
          child: SizedBox(
            width: 500,
            height: 60,
            child: ClipRRect(
              borderRadius: BorderRadius.all(Radius.circular(15)),
              child: ElevatedButton(
                  style: ButtonStyle(
                      backgroundColor:
                          MaterialStateProperty.all(Color(0xFF84693b))),
                  child: Text(
                    widget.answer3,
                    style: TextStyle(
                      color: Colors.white,
                      fontSize: 15,
                    ),
                  ),
                  onPressed: widget.questionsAnswered == false
                      ? () {
                          setState(() {
                            if (widget.iscorrectAnswer3 == true) {
                              ScaffoldMessenger.of(context).showSnackBar(
                                SnackBar(
                                  content: Text('Correct!'),
                                ),
                              );

                              widget.score += 1;
                            } else {
                              disableButton();
                              ScaffoldMessenger.of(context)
                                  .showSnackBar(SnackBar(
                                content: Text('Wrong Answer!'),
                              ));
                            }
                          });
                        }
                      : null),
            ),
          ),
        )
      ],
    );
  }
}

我调用此自定义小部件的主小部件

class Quiz extends StatefulWidget {
  Quiz({Key? key}) : super(key: key);

  int score = 0;

  @override
  _QuizState createState() => _QuizState();
}

class _QuizState extends State<Quiz> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('CyberQuiz'),
        ),
        body: SingleChildScrollView(
            scrollDirection: Axis.vertical,
            child: Column(
              children: [
                Questions(
                  'images/malware_quiz.jpeg',
                  '1. What is a malware?',
                  'Designed to damage computers, servers or any other devices',
                  "Used to get user's credentials",
                  "It's used to destroy networks",
                  '',
                  true,
                  false,
                  false,
                  false,
                ),
              ],
            )));
  }
}

Answer 1

正如您在问题中所建议的那样，您可以创建一个全局变量并increment/decrease/reset那个。

基本示例代码：


import 'package:flutter/material.dart';

class Score {
  static int score = 0;
}

class ScoreCounter extends StatefulWidget {
  const ScoreCounter({Key? key}) : super(key: key);

  @override
  State<ScoreCounter> createState() => _ScoreCounterState();
}

class _ScoreCounterState extends State<ScoreCounter> {
  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        Expanded(
          child: ElevatedButton(
            onPressed: () {
              setState(() {
                Score.score++;
              });
            },
            child: Text('increase score'),
          ),
        ),
        Expanded(child: Text(Score.score.toString()))
      ],
    );
  }
}

另一种选择是使用 Provider 包 - link 这里有一个例子

Provider Package

从所有小部件获取所有分数

Get all the scores from all widgets

flutter

flutter-web