Flutter: void function with parameter can't be executed when I pass to 2 stateless widget-CodePudding

so I encounter this problem. So I have this function

int _questionIndex = 0;
  int _totalScore = 0;

  void _answerQuestion(int score) {
    setState(() {
      _questionIndex = _questionIndex   1;
      _totalScore  = score;
    });
  }

I plan to pass this to 2 widgets, quiz and answers

quiz

import 'package:app_1_starter/answer.dart';
import 'package:app_1_starter/question.dart';
import 'package:flutter/material.dart';

class Quiz extends StatelessWidget {
  final int index;
  final List<Map<String, Object>> questions;
  final Function pressHandler;

  const Quiz(
      {Key? key,
      required this.questions,
      required this.index,
      required this.pressHandler})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Column(
        children: <Widget>[
          Question(questions[index]['question'] as String),
          ...(questions[index]['answers'] as List<Map<String, Object>>)
              .map((answer) {
            return Answer(
              () => pressHandler(answer['score']),
              answer['text'] as String,
            );
          }).toList(),
        ],
      ),
    );
  }
}

the quiz is for when there's only some questions to be answered left.

and this is the answer widget which will provide the answer layout

import 'package:flutter/material.dart';

class Answer extends StatelessWidget {
  final String buttonText;
  final Function pressHandler;

  const Answer(this.pressHandler, this.buttonText, {Key? key})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      margin: const EdgeInsets.all(5),
      child: ElevatedButton(
        style: ButtonStyle(
          backgroundColor: MaterialStateProperty.all(Colors.blue),
        ),
        onPressed: pressHandler(),
        child: Text(
          buttonText,
          style: const TextStyle(color: Colors.white),
        ),
      ),
    );
  }
}

my sdk is environment: sdk: ">=2.17.6 <3.0.0"

the error keeps saying

The following NoSuchMethodError was thrown building Answer(dirty):
Closure call with mismatched arguments: function '_MyAppState.build.<anonymous closure>'
Receiver: Closure: () => ({int score}) => void
Tried calling: _MyAppState.build.<anonymous closure>(30)
Found: _MyAppState.build.<anonymous closure>() => ({int score}) => void

I've tried to put the answer to quiz yet, it keeps giving the same error like above.

I don't know what that means and what went wrong here. Thanks for coming

cheers

CodePudding user response：

thanks to @mmcdon20 for your suggestion the problem is on the main.dart.

It should be like this

Quiz(
 questions: _questions,
 index: _questionIndex,
 pressHandler: _answerQuestion,
)