扑动：支持的语言正在抛出错误（Localizations.of<MaterialLocalizations>（上下文，MaterialLocalizations）returns null）

Question

每次启动我的应用程序时，我都会在日志中收到以下警告：

════════
I/flutter (22601): Warning: This application's locale, de, is not supported by all of its
I/flutter (22601): localization delegates.
I/flutter (22601): > A MaterialLocalizations delegate that supports the de locale was not found.
I/flutter (22601): See flutter.dev/tutorials/internationalization for more
I/flutter (22601): information about configuring an app's locale, supportedLocales,
I/flutter (22601): and localizationsDelegates parameters.
I/flutter (22601):
════════

另外，当尝试使用像AppBar这样的各种小部件时，或者当试图显示一个对话框时，我不能这样做，因为 flutter 会抛出以下断言（异常）：

No MaterialLocalizations found.

因为

Localizations.of<MaterialLocalizations>(context, MaterialLocalizations) == null

断言为真。

德语被列为受支持的语言环境，我在 MaterialApp 中注册了 supportedLanguages 和 localizationDelegates。因为我使用 MaterialApp 作为主根 StatelessWidget，我不明白为什么会抛出这个错误。我已经搜索了，发现的不多，就this old question with no real answer to it, which is the same problem. There is also a GitHub issue这个问题，但好像没有多少人有同样的问题。

Answer 1

对于任何未来 reader，我发现了问题：我没有包含包裹：

flutter_localizations:
  sdk: flutter

并且也不包括 GlobalMaterialLocalization 代表：

localizationsDelegates: [
        S.delegate,
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
      ],

扑动：支持的语言正在抛出错误（Localizations.of<MaterialLocalizations>（上下文，MaterialLocalizations）returns null）

flutter: supported language is throwing error (Localizations.of<MaterialLocalizations>(context, MaterialLocalizations) returns null)

localization

dart

flutter

flutter-widget