我正在構建一個測驗應用程式，并且我創建了一個自定義小部件以節省我很多時間，因為我有很多問題要進行測驗。除了評分系統外，一切都有效。如果我創建同一個小部件的多個實體，分數將不會增加，它將保持為 1。有什么辦法可以將小部件的每個分數傳遞給我的主小部件中的全域變數，這樣我就可以添加所有分數? （我是撲的新手）。
自定義小部件
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),
),
),
)
],
);
}
}
我稱之為自定義小部件的主要小部件
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,
),
],
)));
}
}
uj5u.com熱心網友回復：
正如您在問題中所建議的，您可以創建一個全域變數并增加/減少/重置它。
基本示例代碼：
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()))
],
);
}
}
另一種選擇是使用 Provider 包 - 這里有一個例子的鏈接
提供程式包
轉載請註明出處，本文鏈接：https://www.uj5u.com/qianduan/370366.html
下一篇：保存表格后如何將檔案上傳到檔案夾