您可以创建一个新的AppLocalizations示例，其中包含您想要的句子。
因此，您可以使用.of（context）来获取Locale，而是将所需的Locale提供给AppLocalizations

AppLocalizations(Locale('contry', 'languageSubTag')).translate('SENTENCE_KEY');

希望能帮上忙。

已由本地化解决。override和Builder。更多信息https://docs.flutter.dev/development/accessibility-and-localization/internationalization in“Overriding Locale”

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text(widget.title),
    ),
    body: Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          // Add the following code
          Localizations.override(
            context: context,
            locale: const Locale('es'),
            // Using a Builder to get the correct BuildContext.
            // Alternatively, you can create a new widget and Localizations.override
            // will pass the updated BuildContext to the new widget.
            child: Builder(
              builder: (context) {
                // A toy example for an internationalized Material widget.
                return CalendarDatePicker(
                  initialDate: DateTime.now(),
                  firstDate: DateTime(1900),
                  lastDate: DateTime(2100),
                  onDateChanged: (value) {},
                );
              },
            ),
          ),
        ],
      ),
    ),
  );
}