showBottomSheet抛出错误，抱怨没有脚手架

Question

从LoginPage重定向到登入。在登机时，点击一个按钮，需要显示底部的工作表。使用命名路线进行导航。

稍后在Loginpage中将使用navigator.pushnamed（上下文，'/onboarding')导航到onboarding；重定向。

这是主飞镖

void main() {
  runApp(
    MultiProvider(
      providers: [ChangeNotifierProvider(create: (context) => ThemeModel())],
      child: DevicePreview(
        enabled: !kReleaseMode,
        builder: (context) => MyApp(),
      ),
    ),     
  );
  SystemChrome.setEnabledSystemUIOverlays([]);
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    
    return MaterialApp(
      locale: DevicePreview.of(context).locale, // <--- Add the locale
      builder: DevicePreview.appBuilder, // <--- Add the builder
      theme: Provider.of<ThemeModel>(context).currentTheme,
      debugShowCheckedModeBanner: false,
      initialRoute: '/',
      routes: {
        // When navigating to the "/" route, build the FirstScreen widget.
        '/': (context) => LoginPage(),
        // When navigating to the "/second" route, build the SecondScreen widget.
        '/onboarding': (context) => OnboardingPage(),
        '/home': (context) => Home(),
      },
     
    );
  }
}

  **showBottomSheet(
              context: context,
              builder: (context) => BasicProfileBottomSheetWidget());
  }**
},
child: Text(
  hint,
  style: TextStyle(
    fontSize: 22,
    color: Colors.black,
  ),
),
color: Colors.white,

[38;5;248m════════ Exception caught by gesture ═══════════════════════════════════════════[39;49m
[38;5;244mThe following assertion was thrown while handling a gesture:[39;49m
No Scaffold widget found.

[38;5;244mOnboardingPage widgets require a Scaffold widget ancestor.[39;49m
[38;5;244mThe specific widget that could not find a Scaffold ancestor was: OnboardingPage[39;49m
    [38;5;244mstate: _OnboardingPageState#4c2bb[39;49m
[38;5;244mThe ancestors of this widget were[39;49m
    [38;5;244mMaterialApp[39;49m
        [38;5;244mstate: _MaterialAppState#e362b[39;49m
    [38;5;244mMyApp[39;49m
        [38;5;244mdependencies: [_InheritedProviderScope<ThemeModel>][39;49m
    [38;5;244mDevicePreview[39;49m
        [38;5;244mstate: DevicePreviewState#2a192[39;49m
    [38;5;244mChangeNotifierProvider<ThemeModel>[39;49m
        [38;5;244mvalue: Instance of 'ThemeModel'[39;49m
        [38;5;244mlistening to value[39;49m
    [38;5;244mMultiProvider[39;49m
    [38;5;244m...[39;49m

[38;5;248mTypically, the Scaffold widget is introduced by the MaterialApp or WidgetsApp widget at the top of your application widget tree.[39;49m

[38;5;244mWhen the exception was thrown, this was the stack[39;49m
[38;5;244m#0      debugCheckHasScaffold.<anonymous closure>[39;49m
[38;5;244m#1      debugCheckHasScaffold[39;49m
[38;5;244m#2      showBottomSheet[39;49m
[38;5;248m#3      _getButton.<anonymous closure>[39;49m
[38;5;244m#4      _InkResponseState._handleTap[39;49m
[38;5;244m...[39;49m
[38;5;244mHandler: "onTap"[39;49m
[38;5;244mRecognizer: TapGestureRecognizer#bb0ca[39;49m
    [38;5;244mdebugOwner: GestureDetector[39;49m
    [38;5;244mstate: ready[39;49m
    [38;5;244mwon arena[39;49m
    [38;5;244mfinalPosition: Offset(422.5, 960.5)[39;49m
    [38;5;244mfinalLocalPosition: Offset(166.7, 29.3)[39;49m
    [38;5;244mbutton: 1[39;49m
    [38;5;244msent tap down[39;49m
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

Answer 1

尝试将scaffold小部件紧接在MaterialApp之后，然后onboardingpage可以位于scaffold的主体中