我在flutter中使用了showDialog方法中的Dialog小部件，对话框运行良好，但当对话框打开并且我从设置中更改颜色模式(浅色、深色(时，它会更改整个应用程序的主题，但不会更改对话框主题，直到我关闭并再次打开对话框。知道我该怎么解决这个问题吗？？
创建虚拟项目更改主题
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
final ValueNotifier<ThemeMode> _notifier = ValueNotifier(ThemeMode.light);
bool isLightMode = true;
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.light(),
darkTheme: ThemeData.dark(),
themeMode: ThemeMode.system, // Decides which theme to show, light or dark.
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
/* ElevatedButton(
onPressed: () {
isLightMode ? _notifier.value = ThemeMode.dark : _notifier.value = ThemeMode.light;
setState(() {
isLightMode = !isLightMode;
});
},
child: Text('Toggle Theme'),
),*/
ElevatedButton(
onPressed: () => _showFontDialog(),
child: Text('Show dialog'),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
_showFontDialog() {
showDialog<void>(
context: context,
builder: (BuildContext context) {
return AlertDialog(
insetPadding: EdgeInsets.all(30),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(30),
),
content: StatefulBuilder(
builder: (BuildContext context, StateSetter setState) {
return Container(
child: Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Container(
alignment: Alignment.topLeft,
child: const Text(
'This dialog Change Theme',
style: TextStyle(
fontSize: 20,
fontFamily: 'Roboto',
fontWeight: FontWeight.w600,
),
),
),
SizedBox(
height: 50,
),
/* ElevatedButton(
onPressed: () {
isLightMode ? _notifier.value = ThemeMode.dark : _notifier.value = ThemeMode.light;
setState(() {
isLightMode = !isLightMode;
});
},
child: Text('Toggle Theme'),
),*/
],
),
);
},
),
);
},
);
}
}