我开始使用材质 3 进行颤振。 但是,即使使用默认的基本计数器应用程序,当我添加时:
useMaterial3: true,
应用栏变为白色,没有背景。即使我设置:colorSchemeSeed
这是我的代码:
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
colorSchemeSeed: Colors.red,
useMaterial3: true,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
为什么应用栏变成白色背景?
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headlineMedium,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}
我使用了backgroundColor: Colors.green,然后它就固定了..
class Todo extends StatelessWidget {
const Todo({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primaryColor: Colors.blue,
useMaterial3: true,
),
home: Scaffold(
appBar: AppBar(
title: Text("This is AppBar"),
backgroundColor: Colors.green,
),
),
);
}
}
我不确定,但如果你可以替换 colorSchemeSeed 而不是 PrimaryColor 应该可以工作
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primaryColor: Colors.red,
useMaterial3: true,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}