flutter - 元素类型 'List'无法分配给列表类型 'Widget'

Question

我是新手，我想用他们的选择来迭代问题。问题有单独的小部件，答案有单独的部件。这个问题有多个答案，因此我尝试在其上使用map。我正在学习https://youtu.be/x0uinJvhNxI?t=16739类(class)，但我不知道哪里出错了

main.dart:

import 'question.dart';
import 'answer.dart';

/*void main() {
  runApp(MyApp());
}*/

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return MyAppState();
  }
}

class MyAppState extends State<MyApp> {
  var questionIndex = 0;

  void answerQuestion() {
    setState(() {
      questionIndex += 1;
    });

    print('Answer Chosen');
  }

  @override
  Widget build(BuildContext context) {
    var questions = [
      {
        'questionText': 'What is your favourite color?',
        'options': ['Black', 'Red', 'Green', 'White'],
      },
      {
        'questionText': 'What is your favourite animal?',
        'options': ['Dog', 'Cat', 'Snake', 'Elephant'],
      },
      {
        'questionText': 'Who is your favourite instructor?',
        'options': ['Shree', 'Sthapit', 'Mr Shree', 'Mr Sthapit'],
      }
    ];
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('My First Flutter App'),
        ),
        body: Column(
          children: [
            Question(questions[questionIndex]['questionText']),
          ...(questions[questionIndex]['options'] as List<String>).map((
          answer) {
        return Answer(answerQuestion, answer)
      }).toList()
          ],

        ),
      ),
    );
  }
}

answer.dart:

class Answer extends StatelessWidget {
  final Function answerQuestion;
  final String answerText;

  Answer(this.answerQuestion,this.answerText);

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      margin: EdgeInsets.all(15),
      child: RaisedButton(
          color: Colors.lightBlue,
          textColor: Colors.white,
          child: Text(answerText),
          onPressed: answerQuestion),
    );
  }
}``

Answer 1

我有同样的问题，并通过更新抖动来解决