showBottomSheet 抛出错误，抱怨没有脚手架答案

【问题标题】：showBottomSheet throwing an error complaining no scaffoldshowBottomSheet 抛出错误，抱怨没有脚手架
【发布时间】：2020-11-09 22:09:32
【问题描述】：

从 LoginPage 重定向到 OnBoarding。入职时单击按钮需要显示底部工作表。使用命名路线进行导航。

稍后在登录页面将使用 Navigator.pushNamed(context, '/onboarding');重定向。

这里是 main.dart

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(),
      },
     
    );
  }
}

这里是 buttonClick 然后打开底部表单的代码 sn-p

_getButton(字符串提示，int 索引，BuildContext 上下文) { 返回材质按钮（身高：58，最小宽度：340，形状：RoundedRectangleBorder(borderRadius: new BorderRadius.circular(12)), 按下：（）{ 如果（索引 == 1）{

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

); }

这是我的小部件树

这是错误。

[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

【问题讨论】：

你好，请添加showbottomsheet的代码
谢谢@ByteMe。我刚刚为 showbottomsheet 添加了代码 sn-p

标签： flutter

【解决方案1】：

尝试将Scaffold 小部件紧跟在MaterialApp 之后，然后OnBoardingPage 可以在Scaffold 的主体内

【讨论】：

刚刚粘贴了 main.dart 代码。你能帮我理解如何在 MaterialApp> 之后立即包装 Scaffold
您可以打开OnBoardingPage，第一个小部件应该是Scaffold。对其他页面执行相同操作。单击第一个小部件名称后可以按ALT+ENTER，然后单击Wrap with Widget并将其设置为Scaffold
谢谢。如果您查看屏幕截图，Scaffold 是 OnboardingPage 中的直接小部件。我错过了什么吗？这是相同的代码sn-p。 class _OnboardingPageState extends State { @override Widget build(BuildContext context) { return Scaffold( body: PageView(
也许这就是原因，检查这个答案，它可能有效：stackoverflow.com/a/60161353/6317556
谢谢，该链接中提到的解决方法有效:)

【解决方案2】：

此外，没有使用以下代码的 globalkey 解决方法有效..不知道实际根本原因是什么，但可以修复 :)

showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      backgroundColor: Colors.transparent,
      builder: (context) => Container(
        height: MediaQuery.of(context).size.height * 0.50,
        decoration: new BoxDecoration(
          color: Colors.white,
          borderRadius: new BorderRadius.only(
            topLeft: const Radius.circular(25.0),
            topRight: const Radius.circular(25.0),
          ),
        ),
        child: Center(
          child: Text("Modal content goes here"),
        ),
      ),
    );

【讨论】：