Javascript [react native][ios][react native background fetch]dont'；我不能在ios上工作

我已经在我的应用程序中实现了react native background fetch，它在Android上运行良好，但在ios上运行不好-Xcode 11.4版

模拟后台获取工作。我还注意到后台提取在第一次启动应用程序时触发一次，但现在不再触发了。在Android后台，每15分钟触发一次Fetch

我的配置是：

反应本机：0.62.1

react本机后台提取：2.8.0

这是我的密码：

App.js

class App extends Component {
  componentDidMount () {
    ...
    newPostNotificationService.initNotifications()
    ...

initNotifications = async () => {
  this.configureNotifications() // Configures PushNotification

  BackgroundFetch.registerHeadlessTask(this.fetchNewPosts)

  BackgroundFetch.configure({
    minimumFetchInterval: 15,
    stopOnTerminate: false,
    startOnBoot: true,
    enableHeadless: true
  }, this.fetchNewPosts,
    (error) => {
      console.log(error, '[js] RNBackgroundFetch failed to start')
    })

  BackgroundFetch.status((status) => {
    switch (status) {
      case BackgroundFetch.STATUS_RESTRICTED:
        console.log('BackgroundFetch restricted')
        break
      case BackgroundFetch.STATUS_DENIED:
        console.log('BackgroundFetch denied')
        break
      case BackgroundFetch.STATUS_AVAILABLE:
        console.log('BackgroundFetch is enabled')
        break
    }
  })
}

newPostsNotificationSevice.js

class App extends Component {
  componentDidMount () {
    ...
    newPostNotificationService.initNotifications()
    ...

initNotifications = async () => {
  this.configureNotifications() // Configures PushNotification

  BackgroundFetch.registerHeadlessTask(this.fetchNewPosts)

  BackgroundFetch.configure({
    minimumFetchInterval: 15,
    stopOnTerminate: false,
    startOnBoot: true,
    enableHeadless: true
  }, this.fetchNewPosts,
    (error) => {
      console.log(error, '[js] RNBackgroundFetch failed to start')
    })

  BackgroundFetch.status((status) => {
    switch (status) {
      case BackgroundFetch.STATUS_RESTRICTED:
        console.log('BackgroundFetch restricted')
        break
      case BackgroundFetch.STATUS_DENIED:
        console.log('BackgroundFetch denied')
        break
      case BackgroundFetch.STATUS_AVAILABLE:
        console.log('BackgroundFetch is enabled')
        break
    }
  })
}

fetchNewPostsnewPostsNotificationSevice.js中的方法

async fetchNewPosts(taskId) {
  console.log('BackgroundFetch Start', taskId)

  if (AppState.currentState === 'active') {
    BackgroundFetch.finish(taskId)
    return
  }

  dataStorageService.getSettings().then(async (settings) => {
    if (!settings.notifications) {
      BackgroundFetch.finish(taskId)
      return
    }

    const url = config.API_URL + config.API_ENDPOINTS.POSTS + '&per_page=1&page=1'

    let data
    if (!config.DATA_MOCK.NEW_POSTS) {
      data = await fetch(url)
        .then((response) => {
          return response.json()
        })
        .catch((error) => {
          console.error(error)
        })
    } else {
      data = postsMock.posts
    }

    data = data.map(item => {
      return new PostShort(item)
    })

    data = data.filter(item => {
      return item.sendPush
    })

    if (data.length === 0) {
      BackgroundFetch.finish(taskId)
    }

    dataStorageService.getPostsIndex().then(postsIndex => {
      if (postsIndex.length > 0 && postsIndex.indexOf(data[0].id) !== -1) {
        BackgroundFetch.finish(taskId)
        return
      }

      dataStorageService.getNotificationsIndex().then(notificationsIndex => {
        if (notificationsIndex.indexOf(data[0].id) !== -1) {
          BackgroundFetch.finish(taskId)
          return
        }
        const notificationBody = entities.decode(data[0].title)
        const notificationNumber = notificationsIndex.length + 1
        console.log('notificationNumber', notificationNumber)

        PushNotification.localNotification({
          title: config.NOTIFICATION_TITLE, // (optional)
          message: notificationBody, // (required)
          playSound: true, // (optional) default: true
          soundName: 'default',
          number: notificationNumber,
          id: notificationNumber.toString()
        })

        dataStorageService.insertIntoNotificationsIndex([data[0].id])
        BackgroundFetch.finish(taskId)
      })
    })
  })
}

我按照以下说明进行了iOS设置：

为什么后台抓取不会像Android那样在iOS上定期触发？

好消息：）最后，它起作用了。两天后，iPhone上出现了通知。iOS后台提取算法是有线的。这意味着当模拟后台提取在Xcode中工作时，它应该在一段时间后自动触发。我们只能设置最小频率-15分钟。最大频率是多少？这是个谜。