Flutter后台服务管理插件flutter_background_service_platform_interface的使用

flutter_background_service_platform_interface简介

flutter_background_service_platform_interface 是一个为 flutter_background_service 插件提供的通用平台接口。这个接口允许特定平台实现 flutter_background_service 插件，确保它们支持相同的接口。

使用方法

为了实现一个新的特定平台的 flutter_background_service 实现，你需要扩展 FlutterBackgroundServicePlatform 类，提供执行特定平台行为的实现，并在注册你的插件时，通过调用 FlutterBackgroundServicePlatform.instance = MyPlatformPathProvider() 设置默认的 FlutterBackgroundServicePlatform。

注意事项

强烈建议优先选择非破坏性的变更（例如在接口中添加方法）而不是破坏性的变更。有关为什么一个不太整洁的接口优于破坏性变更的讨论，请参见 https://flutter.dev/go/platform-interface-breaking-changes。

示例代码

下面是一个完整的示例demo，演示了如何使用 flutter_background_service_platform_interface 来创建和管理后台服务：

import 'package:flutter/material.dart';
import 'package:flutter_background_service/flutter_background_service.dart';
import 'package:flutter_background_service_android/flutter_background_service_android.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  initializeService();
  runApp(MyApp());
}

Future<void> initializeService() async {
  final service = FlutterBackgroundService();
  await service.configure(
    androidConfiguration: AndroidConfiguration(
      // this will be executed when app is in foreground or background in separated isolate
      onStart: onStart,
      // auto start service
      autoStart: true,
      isForegroundMode: true,
    ),
    iosConfiguration: IosConfiguration(
      // auto start service
      autoStart: true,
      // this will be called on iOS background fetch
      onFetch: onIosBackgroundFetch,
    ),
  );
}

// to ensure onStart is only called one time when we press the notification start command button.
bool isRunning = false;

void onStart(ServiceInstance service) async {
  if (service is AndroidServiceInstance) {
    service.on('setAsForeground').listen((event) {
      service.setAsForegroundService();
    });

    service.on('setAsBackground').listen((event) {
      service.setAsBackgroundService();
    });
  }

  service.on('stopService').listen((event) {
    service.stopSelf();
  });

  // bring to foreground
  Timer.periodic(Duration(seconds: 1), (timer) async {
    if (!isRunning) {
      isRunning = true;
      // your logic to handle task
      // for example, send location to server every 15 minutes

      // test using external plugin
      final deviceInfo = DeviceInfoPlugin();
      String deviceData = '';
      if (await service.isForegroundService()) {
        if (Platform.isAndroid) {
          final androidInfo = await deviceInfo.androidInfo;
          deviceData = androidInfo.model;
        } else if (Platform.isIOS) {
          final iosInfo = await deviceInfo.iosInfo;
          deviceData = iosInfo.model;
        }
      }

      service.invoke(
        'updateNotification',
        {
          "current_date": DateTime.now().toIso8601String(),
          "device_data": deviceData,
        },
      );

      isRunning = false;
    }
  });
}

void onIosBackgroundFetch(String taskId) async {
  // your logic to handle background fetch for iOS
  // after executing the task, you need to call ServiceController#completeBackgroundTask
  FlutterBackgroundService().completeBackgroundTask(taskId);
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text("Background Service")),
        body: Center(
          child: ElevatedButton(
            onPressed: () async {
              var service = FlutterBackgroundService();
              var status = await service.isRunning();
              if (status) {
                service.invoke("stopService");
              } else {
                service.startService();
              }
            },
            child: Text("Start/Stop Service"),
          ),
        ),
      ),
    );
  }
}

在这个示例中，我们首先初始化了后台服务，配置了Android和iOS的设置。然后定义了 onStart 和 onIosBackgroundFetch 方法来处理服务启动和iOS背景获取的任务。最后，在UI部分，我们提供了一个按钮来启动或停止后台服务。