底部报错如下： ``` flutter: flutter: Handler: "onTap" flutter: Recognizer: flutter: TapGestureRecognizer#59e95 flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════ flutter: Another exception was thrown: No MaterialLocalizations found. ``` 即：__`未配置国际化`__ 本例现象： App支持Android和IOS两种布局，android使用MateriaApp，ios使用CupertinoApp。内部的控件也尽量跟随系统。调用showModalBottomSheet是同一份代码： ``` showModalBottomSheet( context: context, builder: (BuildContext context) => Scaffold(body: Stack(children: <Widget>[ Placeholder(), Placeholder()] ))); ``` __重现步骤：__ 当使用android环境（即MateriaApp风格），showModalBottomSheet正常；使用ios环境报错如上。 检查入口main.dart文件, ``` void main() => runApp(Application()); class Application extends StatelessWidget { // This widget is the root of your application. //ios 主页 Widget iosXApp(BuildContext context) => Theme( data: ThemeData( fontFamily: '.SF Pro Text', ).copyWith(canvasColor: Colors.transparent), child: CupertinoApp( //公共代码略无相关代码略 }, )); Widget androidXApp(BuildContext context) => MaterialApp( //公共代码略无相关代码略 localizationsDelegates: [ const TranslationsDelegate(), GlobalMaterialLocalizations.delegate, GlobalWidgetsLocalizations.delegate, ], supportedLocales: [ const Locale("en", "US"), const Locale("zh", "CN"), ], //略 ); @override Widget build(BuildContext context) { SystemChrome.setPreferredOrientations([ DeviceOrientation.portraitUp, DeviceOrientation.portraitDown, ]); return new AppENV().isIOSPlatform ? iosXApp(context) : androidXApp(context); } } ``` 仔细对比发现，果然在ios的脚手架中__`未配置国际化`__： ``` localizationsDelegates: [ const TranslationsDelegate(), GlobalMaterialLocalizations.delegate, GlobalWidgetsLocalizations.delegate, ], supportedLocales: [ const Locale("en", "US"), const Locale("zh", "CN"), ], ``` 同等加上配置即可。 以上。