Flutter国家信息插件iso_countries的使用

iso_countries 是一个用于从设备操作系统获取ISO国家数据的Flutter插件。它允许你通过传递语言格式（如 “fr-fr”, “de-de”）来获取不同语言的国家名称。所有国家详情都是从操作系统中获取的，而非硬编码。

特点

• 多语言支持：可以获取不同语言的国家名称。
• 系统数据：国家详情直接从操作系统获取，确保最新和准确性。
• 版本更新：
  • 2.1.0：支持Android Embedding V2
  • 2.0.0：支持null safety

注意事项

• Android: 需要API level 21及以上。
• iOS: 如果在运行示例时遇到与pods相关的问题，请删除podfile和podfile.lock并重新运行。

使用方法

获取默认（英语）国家列表

List<Country>? countries;
try {
  countries = await IsoCountries.isoCountries;
} on PlatformException {
  countries = null;
}

根据语言获取国家列表

List<Country>? countries;
try {
  // 例如："fr-fr", "en-en", "de-de"
  countries = await IsoCountries.isoCountriesForLocale('fr-fr');
} on PlatformException {
  countries = null;
}

在Widget中使用

Future<void> prepareDefaultCountries() async {
  List<Country>? countries;
  try {
    countries = await IsoCountries.isoCountries;
  } on PlatformException {
    countries = null;
  }
  if (!mounted) return;

  setState(() {
    if (countries != null) {
      countryList = countries;
    }
  });
}

Future<void> prepareLocaleSpecificCountries() async {
  List<Country>? countries;
  try {
    countries = await IsoCountries.isoCountriesForLocale('fr-fr');
  } on PlatformException {
    countries = null;
  }
  if (!mounted) return;

  setState(() {
    if (countries != null) {
      countryList = countries;
    }
  });
}

根据国家代码和语言标识符获取单个国家对象

Future<void> getCountryForCodeWithIdentifier(String code, String localeIdentifier) async {
  try {
    country = await IsoCountries.isoCountryForCodeForLocale(code, localeIdentifier: localeIdentifier);
  } on PlatformException {
    country = null;
  }
  if (!mounted) return;

  setState(() {
    print(country?.name);
  });
}

示例代码

以下是一个完整的示例代码，展示了如何在Flutter应用中使用iso_countries插件：

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:iso_countries/iso_countries.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  List<Country> countryList = <Country>[];
  Country? country;

  @override
  void initState() {
    super.initState();
    prepareDefaultCountries();
  }

  Future<void> prepareDefaultCountries() async {
    List<Country>? countries;
    try {
      countries = await IsoCountries.isoCountries;
    } on PlatformException {
      countries = null;
    }
    if (!mounted) return;

    setState(() {
      if (countries != null) {
        countryList = countries;
      }
    });
  }

  Future<void> prepareLocaleSpecificCountries() async {
    List<Country>? countries;
    try {
      countries = await IsoCountries.isoCountriesForLocale('fr-fr');
    } on PlatformException {
      countries = null;
    }
    if (!mounted) return;

    setState(() {
      if (countries != null) {
        countryList = countries;
      }
    });
  }

  Future<void> getCountryForCodeWithIdentifier(String code, String localeIdentifier) async {
    try {
      country = await IsoCountries.isoCountryForCodeForLocale(code, localeIdentifier: localeIdentifier);
    } on PlatformException {
      country = null;
    }
    if (!mounted) return;

    setState(() {
      print(country?.name);
    });
  }

  @override
  Widget build(BuildContext context) => MaterialApp(
    home: Scaffold(
      appBar: AppBar(
        actions: [
          TextButton(
            onPressed: prepareLocaleSpecificCountries,
            child: const Text('fr-fr'),
            style: TextButton.styleFrom(primary: Colors.white),
          ),
          TextButton(
            onPressed: prepareDefaultCountries,
            child: const Text('Default'),
            style: TextButton.styleFrom(primary: Colors.white),
          ),
        ],
        title: const Text('Plugin example app'),
      ),
      body: _buildListOfCountries(),
    ),
  );

  Widget _buildListOfCountries() => ListView.builder(
    itemBuilder: (BuildContext context, int index) {
      final Country country = countryList[index];
      return ListTile(
        title: Text(country.name),
        subtitle: Text(country.countryCode),
        onTap: () => getCountryForCodeWithIdentifier(country.countryCode, 'de-de'),
      );
    },
    itemCount: countryList.length,
  );
}

这个示例代码展示了如何初始化和显示国家列表，并提供了切换语言和点击国家以获取详细信息的功能。希望这能帮助你更好地理解和使用iso_countries插件！