无效参数：无效区域设置“en_US”

Question

我成功创建了新支持的语言“rw”（卢旺达语言），您可以更改语言状态，但每次我在语言（“rw”）状态下重新启动应用程序时，都会收到以下错误，有谁知道如何解决这个问题？

The following ArgumentError was thrown building:
Invalid argument(s): Invalid locale "en_US"

When the exception was thrown, this was the stack
#0      _throwLocaleError
package:intl/src/intl_helpers.dart:177
#1      verifiedLocale
package:intl/src/intl_helpers.dart:171
#2      verifiedLocale
package:intl/src/intl_helpers.dart:156
#3      new DateFormat
package:intl/…/intl/date_format.dart:266
#4      new DateFormat.yMEd
package:intl/…/intl/date_format.dart:478

这是我的 rw_intl.dart 文件

import 'dart:async';

import 'package:intl/intl.dart' as intl;
import 'package:intl/date_symbols.dart' as intl;
import 'package:intl/date_symbol_data_custom.dart' as date_symbol_data_custom;
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';

/// A custom set of date patterns for the `rw` locale.
///
/// These are not accurate and are just a clone of the date patterns for the
/// `no` locale to demonstrate how one would write and use custom date patterns.
const rwLocaleDatePatterns = {
  'd': 'd.',
  'E': 'ccc',
  'EEEE': 'cccc',
  'LLL': 'LLL',
  'LLLL': 'LLLL',
  'M': 'L.',
  'Md': 'd.M.',
  'MEd': 'EEE d.M.',
  'MMM': 'LLL',
  'MMMd': 'd. MMM',
  'MMMEd': 'EEE d. MMM',
  'MMMM': 'LLLL',
  'MMMMd': 'd. MMMM',
  'MMMMEEEEd': 'EEEE d. MMMM',
  'QQQ': 'QQQ',
  'QQQQ': 'QQQQ',
  'y': 'y',
  'yM': 'M.y',
  'yMd': 'd.M.y',
  'yMEd': 'EEE d.MM.y',
  'yMMM': 'MMM y',
  'yMMMd': 'd. MMM y',
  'yMMMEd': 'EEE d. MMM y',
  'yMMMM': 'MMMM y',
  'yMMMMd': 'd. MMMM y',
  'yMMMMEEEEd': 'EEEE d. MMMM y',
  'yQQQ': 'QQQ y',
  'yQQQQ': 'QQQQ y',
  'H': 'HH',
  'Hm': 'HH:mm',
  'Hms': 'HH:mm:ss',
  'j': 'HH',
  'jm': 'HH:mm',
  'jms': 'HH:mm:ss',
  'jmv': 'HH:mm v',
  'jmz': 'HH:mm z',
  'jz': 'HH z',
  'm': 'm',
  'ms': 'mm:ss',
  's': 's',
  'v': 'v',
  'z': 'z',
  'zzzz': 'zzzz',
  'ZZZZ': 'ZZZZ',
};

/// A custom set of date symbols for the `rw` locale.
///
/// These are not accurate and are just a clone of the date symbols for the
/// `no` locale to demonstrate how one would write and use custom date symbols.
const rwDateSymbols = {
  'NAME': 'rw',
  'ERAS': <dynamic>[
    'm.Kr.',
    'n.Kr.',
  ],
  'ERANAMES': <dynamic>[
    'mbere ya Kristu',
    'nyuma ya Kristu',
  ],
  'NARROWMONTHS': <dynamic>[
    'M',
    'G',
    'W',
    'M',
    'G',
    'K',
    'N',
    'K',
    'N',
    'U',
    'U',
    'U',
  ],
  'STANDALONENARROWMONTHS': <dynamic>[
    'M',
    'G',
    'W',
    'M',
    'G',
    'K',
    'N',
    'K',
    'N',
    'U',
    'U',
    'U',
  ],
  'MONTHS': <dynamic>[
    'Mutarama',
    'Gashyantare',
    'Werurwe',
    'Mata',
    'Gicurasi',
    'Kamena',
    'Nyakanga',
    'Kanama',
    'Nzeli',
    'Ukwakira',
    'Ugushyingo',
    'Ukuboza',
  ],
  'STANDALONEMONTHS': <dynamic>[
    'Mutarama',
    'Gashyantare',
    'Werurwe',
    'Mata',
    'Gicurasi',
    'Kamena',
    'Nyakanga',
    'Kanama',
    'Nzeli',
    'Ukwakira',
    'Ugushyingo',
    'Ukuboza',
  ],
  'SHORTMONTHS': <dynamic>[
    'Mut.',
    'Gas.',
    'Wer.',
    'Mat.',
    'Gic.',
    'Kam.',
    'Nya.',
    'Kan.',
    'Nze.',
    'Ukw.',
    'Ugu.',
    'Uku.',
  ],
  'STANDALONESHORTMONTHS': <dynamic>[
    'Mut.',
    'Gas.',
    'Wer.',
    'Mat.',
    'Gic.',
    'Kam.',
    'Nya.',
    'Kan.',
    'Nze.',
    'Ukw.',
    'Ugu.',
    'Uku.',
  ],
  'WEEKDAYS': <dynamic>[
    'ku cyumweru',
    'ku wa mbere',
    'ku wa kabiri',
    'ku wa gatatu',
    'ku wa kane',
    'ku wa gatanu',
    'ku wa gatandatu',
  ],
  'STANDALONEWEEKDAYS': <dynamic>[
    'ku cyumweru',
    'ku wa mbere',
    'ku wa kabiri',
    'ku wa gatatu',
    'ku wa kane',
    'ku wa gatanu',
    'ku wa gatandatu',
  ],
  'SHORTWEEKDAYS': <dynamic>[
    'cyumwer.',
    'mbere.',
    'kabiri.',
    'gatatu.',
    'kane.',
    'gatanu.',
    'gatandat.',
  ],
  'STANDALONESHORTWEEKDAYS': <dynamic>[
    'cyumwer.',
    'mbere.',
    'kabiri.',
    'gatatu.',
    'kane.',
    'gatanu.',
    'gatandat.',
  ],
  'NARROWWEEKDAYS': <dynamic>[
    'C',
    'M',
    'K',
    'G',
    'K',
    'G',
    'G',
  ],
  'STANDALONENARROWWEEKDAYS': <dynamic>[
    'C',
    'M',
    'K',
    'G',
    'K',
    'G',
    'G',
  ],
  'SHORTQUARTERS': <dynamic>[
    'K1',
    'K2',
    'K3',
    'K4',
  ],
  'QUARTERS': <dynamic>[
    'kimwe cya kane',
    'bibiri bya kane',
    'bitatu bya kane',
    'bine bya kane',
  ],
  'AMPMS': <dynamic>[
    'za mu gitondo',
    'z\' umugoroba ',
  ],
  'DATEFORMATS': <dynamic>[
    'EEEE d. MMMM y',
    'd. MMMM y',
    'd. MMM y',
    'dd.MM.y',
  ],
  'TIMEFORMATS': <dynamic>[
    'HH:mm:ss zzzz',
    'HH:mm:ss z',
    'HH:mm:ss',
    'HH:mm',
  ],
  'AVAILABLEFORMATS': null,
  'FIRSTDAYOFWEEK': 0,
  'WEEKENDRANGE': <dynamic>[
    5,
    6,
  ],
  'FIRSTWEEKCUTOFFDAY': 3,
  'DATETIMEFORMATS': <dynamic>[
    '{1} {0}',
    '{1} \'kl\'. {0}',
    '{1}, {0}',
    '{1}, {0}',
  ],
};

class _RwMaterialLocalizationsDelegate
    extends LocalizationsDelegate<MaterialLocalizations> {
  const _RwMaterialLocalizationsDelegate();

  @override
  bool isSupported(Locale locale) => locale.languageCode == 'rw';

  @override
  Future<MaterialLocalizations> load(Locale locale) async {
    final String localeName = intl.Intl.canonicalizedLocale(locale.toString());

    // The locale (in this case `rw`) needs to be initialized into the custom
    // date symbols and patterns setup that Flutter uses.
    date_symbol_data_custom.initializeDateFormattingCustom(
      locale: localeName,
      patterns: rwLocaleDatePatterns,
      symbols: intl.DateSymbols.deserializeFromMap(rwDateSymbols),
    );

    return SynchronousFuture<MaterialLocalizations>(
      RwMaterialLocalizations(
        localeName: localeName,
        // The `intl` library's NumberFormat class is generated from CLDR data
        // (see https://github.com/dart-lang/intl/blob/master/lib/number_symbols_data.dart).
        // Unfortunately, there is no way to use a locale that isn't defined in
        // this map and the only way to work around this is to use a listed
        // locale's NumberFormat symbols. So, here we use the number formats
        // for 'en_US' instead.
        decimalFormat: intl.NumberFormat('#,##0.###', 'en_US'),
        twoDigitZeroPaddedFormat: intl.NumberFormat('00', 'en_US'),
        // DateFormat here will use the symbols and patterns provided in the
        // `date_symbol_data_custom.initializeDateFormattingCustom` call above.
        // However, an alternative is to simply use a supported locale's
        // DateFormat symbols, similar to NumberFormat above.
        fullYearFormat: intl.DateFormat('y', localeName),
        compactDateFormat: intl.DateFormat('yMd', localeName),
        shortDateFormat: intl.DateFormat('yMMMd', localeName),
        mediumDateFormat: intl.DateFormat('EEE, MMM d', localeName),
        longDateFormat: intl.DateFormat('EEEE, MMMM d, y', localeName),
        yearMonthFormat: intl.DateFormat('MMMM y', localeName),
        shortMonthDayFormat: intl.DateFormat('MMM d', localeName),
      ),
    );
  }

  @override
  bool shouldReload(_RwMaterialLocalizationsDelegate old) => false;
}

/// A custom set of localizations for the 'rw' locale. In this example, only
/// the value for openAppDrawerTooltip was modified to use a custom message as
/// an example. Everything else uses the American English (en_US) messages
/// and formatting.
class RwMaterialLocalizations extends GlobalMaterialLocalizations {
  const RwMaterialLocalizations({
    String localeName = 'rw',
    @required intl.DateFormat fullYearFormat,
    @required intl.DateFormat compactDateFormat,
    @required intl.DateFormat shortDateFormat,
    @required intl.DateFormat mediumDateFormat,
    @required intl.DateFormat longDateFormat,
    @required intl.DateFormat yearMonthFormat,
    @required intl.DateFormat shortMonthDayFormat,
    @required intl.NumberFormat decimalFormat,
    @required intl.NumberFormat twoDigitZeroPaddedFormat,
  }) : super(
          localeName: localeName,
          fullYearFormat: fullYearFormat,
          compactDateFormat: compactDateFormat,
          shortDateFormat: shortDateFormat,
          mediumDateFormat: mediumDateFormat,
          longDateFormat: longDateFormat,
          yearMonthFormat: yearMonthFormat,
          shortMonthDayFormat: shortMonthDayFormat,
          decimalFormat: decimalFormat,
          twoDigitZeroPaddedFormat: twoDigitZeroPaddedFormat,
        );

  @override
  String get moreButtonTooltip => r'Ibindi';

  @override
  String get aboutListTileTitleRaw => r'Ibijyanye $applicationName';

  @override
  String get alertDialogLabel => r'Imenyesha';

  @override
  String get anteMeridiemAbbreviation => r'AM';

  @override
  String get backButtonTooltip => r'Inyuma';

  @override
  String get cancelButtonLabel => r'HAGARIKA';

  @override
  String get closeButtonLabel => r'FUNGA';

  @override
  String get closeButtonTooltip => r'Funga';

  @override
  String get collapsedIconTapHint => r'Agura';

  @override
  String get continueButtonLabel => r'KOMEZA';

  @override
  String get copyButtonLabel => r'KOPIYA';

  @override
  String get cutButtonLabel => r'KATINGA';

  @override
  String get deleteButtonTooltip => r'Siba';

  @override
  String get dialogLabel => r'Ikiganiro';

  @override
  String get drawerLabel => r'Ibikubiyemo';

  @override
  String get expandedIconTapHint => r'Gabanya';

  @override
  String get hideAccountsLabel => r'Hishya konte';

  @override
  String get licensesPageTitle => r'Licenses';

  @override
  String get modalBarrierDismissLabel => r'Dismiss';

  @override
  String get nextMonthTooltip => r'Ukwezi gutaha';

  @override
  String get nextPageTooltip => r'Paji ikurikira';

  @override
  String get okButtonLabel => r'KOMEZA';

  @override
  // A custom drawer tooltip message.
  String get openAppDrawerTooltip => r'Custom Navigation Menu Tooltip';

  @override
  String get pageRowsInfoTitleRaw => r'$firstRow–$lastRow of $rowCount';

  @override
  String get pageRowsInfoTitleApproximateRaw =>
      r'$firstRow–$lastRow of about $rowCount';

  @override
  String get pasteButtonLabel => r'PASTE';

  @override
  String get popupMenuLabel => r'Popup menu';

  @override
  String get postMeridiemAbbreviation => r'PM';

  @override
  String get previousMonthTooltip => r'Ukwezi gushize';

  @override
  String get previousPageTooltip => r'Paji ibanza';

  @override
  String get refreshIndicatorSemanticLabel => r'Refresh';

  @override
  String get remainingTextFieldCharacterCountFew => null;

  @override
  String get remainingTextFieldCharacterCountMany => null;

  @override
  String get remainingTextFieldCharacterCountOne => r'inyuguti imwe isigaye';

  @override
  String get remainingTextFieldCharacterCountOther =>
      r'inyuguti $remainingCount zisigaye';

  @override
  String get remainingTextFieldCharacterCountTwo => null;

  @override
  String get remainingTextFieldCharacterCountZero => r'Nta nyuguti isigaye';

  @override
  String get reorderItemDown => r'Manuka';

  @override
  String get reorderItemLeft => r'Jya ibumoso';

  @override
  String get reorderItemRight => r'Jya iburyo';

  @override
  String get reorderItemToEnd => r'Manuka ahahera';

  @override
  String get reorderItemToStart => r'Zamuka ahabanza';

  @override
  String get reorderItemUp => r'Zamuka';

  @override
  String get rowsPerPageTitle => r'Rows per page:';

  @override
  ScriptCategory get scriptCategory => ScriptCategory.englishLike;

  @override
  String get searchFieldLabel => r'Ishakiro';

  @override
  String get selectAllButtonLabel => r'HITAMO BYOSE';

  @override
  String get selectedRowCountTitleFew => null;

  @override
  String get selectedRowCountTitleMany => null;

  @override
  String get selectedRowCountTitleOne => r'1 item selected';

  @override
  String get selectedRowCountTitleOther => r'$selectedRowCount items selected';

  @override
  String get selectedRowCountTitleTwo => null;

  @override
  String get selectedRowCountTitleZero => r'No items selected';

  @override
  String get showAccountsLabel => r'Garagaza konte';

  @override
  String get showMenuTooltip => r'Garagaza Ibikubiyemo';

  @override
  String get signedInLabel => r'Winjiye';

  @override
  String get tabLabelRaw => r'Tab $tabIndex of $tabCount';

  @override
  TimeOfDayFormat get timeOfDayFormatRaw => TimeOfDayFormat.h_colon_mm_space_a;

  @override
  String get timePickerHourModeAnnouncement => r'Hitamo amasaha';

  @override
  String get timePickerMinuteModeAnnouncement => r'Hitamo iminota';

  @override
  String get viewLicensesButtonLabel => r'VIEW LICENSES';

  @override
  List<String> get narrowWeekdays =>
      const <String>['C', 'M', 'K', 'G', 'K', 'G', 'G'];

  @override
  int get firstDayOfWeekIndex => 0;

  static const LocalizationsDelegate<MaterialLocalizations> delegate =
      _RwMaterialLocalizationsDelegate();

  @override
  String get calendarModeButtonLabel => r'Jya kuri kalendari';

  @override
  String get dateHelpText => r'mm/dd/yyyy';

  @override
  String get dateInputLabel => r'Injiza itariki';

  @override
  String get dateOutOfRangeLabel => r'Out of range.';

  @override
  String get datePickerHelpText => r'HITAMO ITARIKI';

  @override
  String get dateRangeEndDateSemanticLabelRaw => r'Itariki ihera $fullDate';

  @override
  String get dateRangeEndLabel => r'Itariki ihera';

  @override
  String get dateRangePickerHelpText => 'HITAMO INTERA';

  @override
  String get dateRangeStartDateSemanticLabelRaw => 'Itariki ibanza \$fullDate';

  @override
  String get dateRangeStartLabel => 'Itariki ibanza';

  @override
  String get dateSeparator => '/';

  @override
  String get dialModeButtonLabel => 'Switch to dial picker mode';

  @override
  String get inputDateModeButtonLabel => 'Switch to input';

  @override
  String get inputTimeModeButtonLabel => 'Switch to text input mode';

  @override
  String get invalidDateFormatLabel => 'Invalid format.';

  @override
  String get invalidDateRangeLabel => 'Invalid range.';

  @override
  String get invalidTimeLabel => 'Enter a valid time';

  @override
  String get licensesPackageDetailTextOther => '\$licenseCount licenses';

  @override
  String get saveButtonLabel => 'BIKA';

  @override
  String get selectYearSemanticsLabel => 'Hitamo umwaka';

  @override
  String get timePickerDialHelpText => 'HITAMO IGIHE';

  @override
  String get timePickerHourLabel => 'Isaha';

  @override
  String get timePickerInputHelpText => 'INJIZA GIHE';

  @override
  String get timePickerMinuteLabel => 'Umunota';

  @override
  String get unspecifiedDate => 'Itariki';

  @override
  String get unspecifiedDateRange => 'Date Range';
}

这是我的 main.dart 文件

`locale: _locale,
supportedLocales: [
Locale('en'),
Locale('rw'),
],
localizationsDelegates: [
DemoLocalization.delegate,
GlobalMaterialLocalizations.delegate,
GlobalWidgetsLocalizations.delegate,
GlobalCupertinoLocalizations.delegate,
RwMaterialLocalizations.delegate,
],

        localeResolutionCallback: (deviceLocale, supportedLocales) {
          for (var locale in supportedLocales) {
            if (locale.languageCode == deviceLocale.languageCode) {
              return deviceLocale;
            }
          }
          return supportedLocales.first;
        },`

Answer 1

问题是您已将支持的区域设置设置为：

   supportedLocales: [
Locale('en'),
Locale('rw'),
],

将 Locale('en') 替换为 Locale('en_US')，因为错误提示。您收到错误的原因是您的设备区域设置是 en_US 而不是 en。 最好的方法是集中您支持的区域设置。如果您的代码编辑器（VS code 或 Android Studio）中有 intl 插件，那么您应该有这个生成的文件夹（lib/ generated/l10n.dart）。在此文件中，您将找到一个名为 AppLocalizationDelegate 的类，在该类中您将找到 supportedLocales 的列表。在你的 main.dart 中调用这个列表

import 'package:your_package_name_here/generated/l10n.dart';

supportedLocales: AppLocalizationDelegate().supportedLocales,

Answer 2

supportedLocales: [
Locale('en', 'Us),

],