1-) FLUTTER - Çoklu dil desteği ekleme localizations kullanımı tr en de ru easy localization ile

EKRAN GÖRÜNTÜSÜ

UYARI GETX İLE KULLANIYORSAN EXTENSİON OLUŞTUR

1. ADIM StringLocalization.dart diye dosya oluştur ve title: Text('MyApp'.localized), //şeklide kullan

1-) pubspec.yaml

easy_localization: ^3.0.0     # bu kütüphane ile yapıcaz ama  flutter_localizations danda yararlancaz

dropdown_button2: ^1.2.1  # dropdownbutton ile bayrak seçmek için

dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_localizations: # yararlancaz

    sdk: flutter

assets:
  - assets/images/    # yolları tanıtmayı unutma

  - assets/languages/   # yolları tanıtmaya unutma

2-)  assets/languages/ klasörü

3-) LocaleKeys.dart

import 'dart:ui';
import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/material.dart';
import 'AppConstant.dart';
import 'CustomButtonTest.dart';

abstract class LocaleKeys {
  static const hello= 'hello';

  static String suankiDil = "assets/images/turkce.png";

static setLocale(BuildContext context, MenuItem item) {
  switch (item) {
    case MenuItems.turkce:
      LocaleKeys.suankiDil = "assets/images/turkce.png";
      context.setLocale(AppConstant.TR_LOCALE);
      break;
    case MenuItems.ingilizce:
      LocaleKeys.suankiDil = "assets/images/ingilizce.png";
      context.setLocale(AppConstant.EN_LOCALE);
      break;
    case MenuItems.rusca:
      LocaleKeys.suankiDil = "assets/images/rusca.png";
      context.setLocale(AppConstant.RU_LOCALE);
      break;
    case MenuItems.almanca:
      LocaleKeys.suankiDil = "assets/images/almanca.png";
      context.setLocale(AppConstant.DE_LOCALE);
      break;
  }
}

static Locale? varsayilanTelefonunDili(
    Locale? locale, Iterable<Locale> supportedLocales) {
  // Aktif edilecek parametre
  /// [locale]: Cihazın dili null değilse
  if (locale != null) {
    switch (locale.languageCode) {
      case "tr":
        LocaleKeys.suankiDil = "assets/images/turkce.png";
        break;
      case "en":
        LocaleKeys.suankiDil = "assets/images/ingilizce.png";
        break;
      case "de":
        LocaleKeys.suankiDil = "assets/images/almanca.png";
        break;
      case "ru":
        LocaleKeys.suankiDil = "assets/images/rusca.png";
        break;
    }

    debugPrint(
        "Algılanan cihaz dili: Dil Kodu: ${locale.languageCode}, Ülke Kodu: ${locale.countryCode}");

    for (var supportedLocale in supportedLocales) {
      /// Cihazın dil kodu desteklenen diller arasındaki dil kodlarının içinde var mı?
      if (supportedLocale.languageCode == locale.languageCode) {
        /// Varsa desteklenen dili döndür

        switch (locale.languageCode) {
          case "tr":
            return AppConstant.TR_LOCALE;
          case "en":
            return AppConstant.EN_LOCALE;
          case "de":
            return AppConstant.DE_LOCALE;
          case "ru":
            return AppConstant.RU_LOCALE;
        }
      }
    }
  }
  debugPrint("Algılanan cihaz dili desteklenen diller arasında bulunmuyor.");

  /// [locale]: Cihazın dili null ise
  /// Yoksa [supportedLocales] Listesindeki ilk sonucu döndür.
  debugPrint(
      "Uygulamanın başlatılması istenen dil: Dil Kodu: ${supportedLocales.first.languageCode}, Ülke Kodu: ${supportedLocales.first.countryCode}");
  return AppConstant.TR_LOCALE;
}

}

4-) CustomButtonTest.dart

import 'package:dropdown_button2/dropdown_button2.dart';
import 'package:flutter/material.dart';

import 'LocaleKeys.dart';

class CustomButtonTest extends StatefulWidget {
  const CustomButtonTest({Key? key}) : super(key: key);

  @override
  State<CustomButtonTest> createState() => _CustomButtonTestState();
}

class _CustomButtonTestState extends State<CustomButtonTest> {
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return DropdownButtonHideUnderline(
      child: DropdownButton2(
        customButton: Container(
          alignment: Alignment.center,
          
          child: Padding(
            padding: EdgeInsets.all(5),
            child: Row(children: [
              Image.asset(LocaleKeys.suankiDil),
              Icon(Icons.arrow_downward)
            ],),
          ),
        ),
        customItemsIndexes: const [4],
        customItemsHeight: 8,
        items: [
          ...MenuItems.firstItems.map(
            (item) => DropdownMenuItem<MenuItem>(
              value: item,
              child: MenuItems.buildItem(item),
            ),
          ),

        ],
        onChanged: (value) {
          MenuItems.onChanged(context, value as MenuItem);
        },
        itemHeight: 55,
        itemPadding: const EdgeInsets.only(left: 16, right: 16),
        dropdownWidth: 180,
        dropdownPadding: const EdgeInsets.symmetric(vertical: 6),
        dropdownDecoration: BoxDecoration(
          borderRadius: BorderRadius.circular(4),
          color: Colors.white,
        ),
        dropdownElevation: 8,
        offset: const Offset(0, 8),
      ),
    );
  }
}

class MenuItem {
  final String text;
  final String logo;

  const MenuItem({
    required this.text,
    required this.logo,
  });
}

class MenuItems {
  static const List<MenuItem> firstItems = [turkce, ingilizce, almanca,rusca];

  static const turkce =
      MenuItem(text: 'Türkçe', logo: "assets/images/turkce.png");
  static const ingilizce =
      MenuItem(text: 'English', logo: "assets/images/ingilizce.png");
  static const almanca =
      MenuItem(text: 'Deutsche', logo: "assets/images/almanca.png");
  static const rusca =
      MenuItem(text: 'русский', logo: "assets/images/rusca.png");

  static Widget buildItem(MenuItem item) {
    return Row(
      children: [
        Container(
          width: 42,
          height: 30,
          decoration: BoxDecoration(
            color: Colors.orange,
            shape: BoxShape.rectangle,
            image: new DecorationImage(
              image: AssetImage(item.logo),
              fit: BoxFit.cover,
            ),
          ),
        ),
        const SizedBox(
          width: 10,
        ),
        Text(
          item.text,
          style: const TextStyle(
              color: Colors.black, fontWeight: FontWeight.bold, fontSize: 13),
        ),
      ],
    );
  }

  static onChanged(BuildContext context, MenuItem item) {
   LocaleKeys.setLocale(context, item);
  }
}

5-) AppConstant.dart

import 'package:flutter/widgets.dart';

class AppConstant {
  static const TR_LOCALE = Locale("tr", "TR");
  static const EN_LOCALE = Locale("en", "US");
  static const RU_LOCALE = Locale("ru", "RU");
  static const DE_LOCALE = Locale("de", "DE");
  static const LANG_PATH = "assets/languages";

  static const SUPPORTED_LOCALE = [
    AppConstant.EN_LOCALE,
    AppConstant.TR_LOCALE,
    AppConstant.DE_LOCALE,
    AppConstant.RU_LOCALE,
  ];
}

6-) main.dart

import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:rmosflutterguest/langs/LocaleKeys.dart';
import 'langs/AppConstant.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await EasyLocalization.ensureInitialized();

  runApp(
    EasyLocalization(
      supportedLocales: AppConstant.SUPPORTED_LOCALE,
      path: AppConstant.LANG_PATH,
      //fallbackLocale: Locale('tr','TR'),
      child: MyApp(),
    ),
  );
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);
  static const String _title = 'Flutter Code Sample';
  @override
  State<MyApp> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      localizationsDelegates: context.localizationDelegates,
      supportedLocales: context.supportedLocales,
      title: MyApp._title,
      locale: context.locale,
      home: Row(
                      children: [
                      SizedBox(
                                    width: 20,
                              ),
                                   Card(
                       child: Container(
                              child: CustomButtonTest(),
                            ),
                         ),

                        ],
                           ),
      //BottomNavigationPage(), // LoginPage1()
      builder: EasyLoading.init(),
      localeResolutionCallback: LocaleKeys.varsayilanTelefonunDili,
    );
  }
}

7-) BAYRAKLAR

bayraklar : https://github.com/madebybowtie/FlagKit/blob/master/Assets/Flags.md

8-) KULLANIMI

KULLANIMI : Text(LocaleKeys.hello.tr())   veya Text('hello').tr() veya   tr('hello')  veya print('hello'.tr());

DİL DEĞİŞTİRMEK İÇİN : onPressed: () {LocaleKeys.setLocale(context, item); } veya context.setLocale(AppConstant.EN_LOCALE);

VARSAYILAN TELEFONUN DİLİ : LocaleKeys.varsayilanTelefonunDili

9-) KAYNAK

kaynak : https://www.mobiler.dev/post/flutter-da-coklu-dil-destegi-localization

kaynak : https://pub.dev/packages/easy_localization/example