Flutter空气质量查询插件 air_quality 的使用

air_quality 插件可以帮助开发者从 World’s Air Quality Index 服务中获取空气质量指数。以下是该插件的详细使用说明和一个完整的示例 Demo。

权限要求

无需任何特殊权限即可使用此插件。

使用方法

导入依赖

首先，确保在您的项目中添加了 air_quality 依赖，并导入必要的包：

import 'package:air_quality/air_quality.dart';

初始化

为了进行查询，您需要一个 API Key。可以从这里获取 API Key。初始化 AirQuality 对象如下：

String key = 'XXX38456b2b85c92647d8b65090e29f957638c77'; // 替换为您的实际API Key
AirQuality airQuality = AirQuality(key);

获取空气质量数据

以下是几种不同的方式来获取空气质量数据：

通过城市名称查询（如慕尼黑）

AirQualityData feedFromCity = await airQuality.feedFromCity('munich');

通过站点ID查询（如哥德堡气象站）

AirQualityData feedFromStationId = await airQuality.feedFromStationId('7867');

通过地理坐标查询（如柏林）

AirQualityData feedFromGeoLocation = await airQuality.feedFromGeoLocation('52.6794', '12.5346');

通过IP地址查询

AirQualityData fromIP = await airQuality.feedFromIP();

示例Demo

下面是一个完整的Flutter应用程序示例，演示如何集成并使用 air_quality 插件来显示不同来源的空气质量信息：

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

enum AppState { NOT_DOWNLOADED, DOWNLOADING, FINISHED_DOWNLOADING }

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Air Quality Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Air Quality Demo'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, this.title}) : super(key: key);

  final String? title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  String _key = 'YOUR_API_KEY'; // 替换为您的实际API Key
  late AirQuality _airQuality;
  AppState _state = AppState.NOT_DOWNLOADED;
  late List<AirQualityData> _data;

  @override
  void initState() {
    super.initState();
    _airQuality = AirQuality(_key);
  }

  Future<void> download() async {
    _data = [];

    setState(() {
      _state = AppState.DOWNLOADING;
    });

    // Fetch data using different methods
    var feeds = await Future.wait([
      _airQuality.feedFromCity('munich'),
      _airQuality.feedFromStationId('7867'),
      _airQuality.feedFromGeoLocation(52.6794, 12.5346),
      _airQuality.feedFromIP(),
    ]);

    setState(() {
      _data.addAll(feeds);
      _state = AppState.FINISHED_DOWNLOADING;
    });
  }

  Widget contentFinishedDownload() {
    return Center(
      child: ListView.separated(
        itemCount: _data.length,
        itemBuilder: (context, index) {
          return ListTile(
            title: Text(_data[index].toString()),
          );
        },
        separatorBuilder: (context, index) {
          return Divider();
        },
      ),
    );
  }

  Widget contentDownloading() {
    return Container(
      margin: EdgeInsets.all(25),
      child: Column(children: [
        Text(
          'Fetching Air Quality...',
          style: TextStyle(fontSize: 20),
        ),
        Container(
          margin: EdgeInsets.only(top: 50),
          child: Center(child: CircularProgressIndicator(strokeWidth: 10)),
        ),
      ]),
    );
  }

  Widget contentNotDownloaded() {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Text(
            'Press the button to download the Air Quality',
          ),
        ],
      ),
    );
  }

  Widget showContent() {
    if (_state == AppState.FINISHED_DOWNLOADING) return contentFinishedDownload();
    if (_state == AppState.DOWNLOADING) return contentDownloading();
    return contentNotDownloaded();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title!),
      ),
      body: showContent(),
      floatingActionButton: FloatingActionButton(
        onPressed: download,
        tooltip: 'Download',
        child: Icon(Icons.cloud_download),
      ),
    );
  }
}

请确保将 _key 替换为您自己的API密钥。这个示例展示了如何根据不同的参数获取空气质量数据，并以列表的形式展示出来。