Flutter地理编码插件geocoding_ohos的使用

geocoding_ohos 插件提供了地理编码和逆地理编码的功能。它是对 [geocoding][1] 的实现。

使用方法

在 pubspec.yaml 文件中添加以下依赖：

dependencies:
  geocoding: 3.0.0
  geocoding_ohos: 1.0.0

此包是[支持的][2]，这意味着您可以直接使用 geocoding，当您这样做时，此包会自动包含在您的应用程序中。以下是一些核心功能和方法的使用示例：

导入插件

import 'package:geocoding_ohos/geocoding_ohos.dart';

实例化 GeocodingOhos 类

GeocodingOhos _geocodingOhos = GeocodingOhos();

示例：从给定坐标获取位置标记

_geocodingOhos.placemarkFromCoordinates(latitude, longitude).then((placemarks) {
  var output = '未找到结果。';
  if (placemarks.isNotEmpty) {
    output = placemarks[0].toString(); // 将第一个结果转换为字符串
  }
});

示例：从给定地址获取位置标记

_geocodingOhos.placemarkFromAddress(_addressController.text).then((locations) {
  var output = '未找到结果。';
  if (locations.isNotEmpty) {
    output = locations[0].toString(); // 将第一个结果转换为字符串
  }
});

示例：从给定地址获取地理位置

_geocodingOhos.locationFromAddress(_addressController.text).then((locations) {
  var output = '未找到结果。';
  if (locations.isNotEmpty) {
    output = locations[0].toString(); // 将第一个结果转换为字符串
  }
});

示例：检查地理编码服务是否可用

_geocodingOhos.isPresent().then((isPresent) {
  var output = isPresent ? "地理编码器可用" : "地理编码器不可用";
});

示例：设置区域标识符（如 en_US, nl_NL, zh_CN 等）

_geocodingOhos.setLocaleIdentifier("zh_CN").then((_) {
  // 设置成功后可以执行其他操作
});

完整示例代码

以下是完整的示例代码，展示如何在 Flutter 应用程序中使用 geocoding_ohos 插件。

main.dart

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

void main() {
  runApp(BaseflowPluginExample());
}

/// A Flutter application demonstrating the functionality of this plugin
class BaseflowPluginExample extends StatelessWidget {
  final MaterialColor themeMaterialColor =
      createMaterialColor(const Color.fromRGBO(48, 49, 60, 1));

  [@override](/user/override)
  Widget build(BuildContext context) {
    final ThemeData theme = ThemeData();
    return MaterialApp(
      title: 'Baseflow 地理编码插件示例',
      theme: theme.copyWith(
        scaffoldBackgroundColor: const Color.fromRGBO(48, 49, 60, 0.8),
        colorScheme: theme.colorScheme.copyWith(
          secondary: Colors.white60,
          primary: createMaterialColor(const Color.fromRGBO(48, 49, 60, 1)),
          background: const Color.fromRGBO(48, 49, 60, 0.8),
        ),
        bottomAppBarTheme: theme.bottomAppBarTheme.copyWith(
          color: const Color.fromRGBO(57, 58, 71, 1),
        ),
        buttonTheme: ButtonThemeData(
          buttonColor: themeMaterialColor.shade500,
          disabledColor: themeMaterialColor.withRed(200),
          splashColor: themeMaterialColor.shade50,
          textTheme: ButtonTextTheme.primary,
        ),
        hintColor: themeMaterialColor.shade500,
        textTheme: TextTheme(
          bodyLarge: TextStyle(
            color: Colors.white,
            fontSize: 16,
            height: 1.3,
          ),
          bodyMedium: TextStyle(
            color: Colors.white,
            fontSize: 18,
            height: 1.2,
          ),
          labelLarge: TextStyle(color: Colors.white),
          displayLarge: TextStyle(
            color: Colors.white,
            fontSize: 18,
          ),
        ),
        visualDensity: VisualDensity.adaptivePlatformDensity,
        inputDecorationTheme: InputDecorationTheme(
          fillColor: const Color.fromRGBO(37, 37, 37, 1),
          filled: true,
        ),
      ),
      home: AppHome(title: 'Baseflow 地理编码插件示例'),
    );
  }

  /// Creates a [MaterialColor] based on the supplied [Color]
  static MaterialColor createMaterialColor(Color color) {
    final strengths = <double>[.05];
    final swatch = <int, Color>{};
    final r = color.red, g = color.green, b = color.blue;
    for (var i = 1; i < 10; i++) {
      strengths.add(0.1 * i);
    }
    for (var strength in strengths) {
      final ds = 0.5 - strength;
      swatch[(strength * 1000).round()] = Color.fromRGBO(
        r + ((ds < 0 ? r : (255 - r)) * ds).round(),
        g + ((ds < 0 ? g : (255 - g)) * ds).round(),
        b + ((ds < 0 ? b : (255 - b)) * ds).round(),
        1,
      );
    }
    return MaterialColor(color.value, swatch);
  }
}

/// A Flutter example demonstrating how the 地理编码插件 could be used
class AppHome extends StatefulWidget {
  AppHome({required this.title});

  final String title;

  [@override](/user/override)
  _AppHomeState createState() => _AppHomeState();
}

class _AppHomeState extends State<AppHome> {
  final _pageController = PageController(initialPage: 0);
  var _currentPage = 0;

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).appBarTheme.backgroundColor,
        title: Center(
          child: Image.asset(
            'res/images/baseflow_logo_def_light-02.png',
            width: 140,
          ),
        ),
      ),
      body: PageView(
        controller: _pageController,
        children: pages,
        onPageChanged: (page) {
          setState(() {
            _currentPage = page;
          });
        },
      ),
      bottomNavigationBar: _bottomAppBar(),
    );
  }

  BottomAppBar _bottomAppBar() {
    return BottomAppBar(
      elevation: 5,
      color: Theme.of(context).bottomAppBarTheme.color,
      child: Row(
        mainAxisSize: MainAxisSize.max,
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: List.unmodifiable(() sync* {
          for (var i = 0; i < pages.length; i++) {
            yield Expanded(
              child: IconButton(
                iconSize: 30,
                icon: Icon(icons.elementAt(i)),
                color: _bottomAppBarIconColor(i),
                onPressed: () => _animateToPage(i),
              ),
            );
          }
        }()),
      ),
    );
  }

  void _animateToPage(int page) {
    _pageController.animateToPage(page,
        duration: Duration(milliseconds: 200), curve: Curves.linear);
  }

  Color _bottomAppBarIconColor(int page) {
    return _currentPage == page
        ? Colors.white
        : Theme.of(context).colorScheme.secondary;
  }
}