如何在Flutter iOS和安卓应用中进行周期性的后台拉取？

import 'package:workmanager/workmanager.dart';

void scheduleBackgroundFetch() {
  Workmanager().initialize(
    callbackDispatcher,
    isInDebugMode: true,
  );

  final backgroundFetch = BackgroundFetch.configure(
    () async {
      // 执行后台任务
      print("Background fetch running");
      // 完成任务后调用complete
      BackgroundFetch.complete();
    },
    minimumFetchInterval: Duration(hours: 1),
  );

  backgroundFetch.registerWithWorkmanager();
}

void callbackDispatcher() {
  Workmanager().executeTask((task, inputData) {
    // 处理任务
    return Future.value(true);
  });
}

<key>UIBackgroundModes</key>
<array>
  <string>fetch</string>
</array>

import 'package:flutter/services.dart';

void scheduleBackgroundFetch() {
  const platform = MethodChannel('com.example.backgroundfetch');
  platform.invokeMethod('scheduleBackgroundFetch');
}

func application(_ application: UIApplication, performFetchWithCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
  // 执行后台任务
  completionHandler(.newData)
}