当我到达该位置时，如何进行后台网络通话？

Question

当在后台更改位置时，我想将位置更新到服务器。每次收到重大位置更改时，我都希望有一种安全的方式来更新后台位置。如何拨打网络电话？

 func endBackgroundUpdateTask() {
        UIApplication.shared.endBackgroundTask(self.backgroundUpdateTask)
        self.backgroundUpdateTask = UIBackgroundTaskInvalid
    }


    func scheduledLocationManager(_ manager: APScheduledLocationManager, didUpdateLocations locations: [CLLocation]) {
        print(locations.last?.description ?? "no location")
        self.backgroundUpdateTask = UIApplication.shared.beginBackgroundTask(expirationHandler: {
            Alamofire.request("https://testomkar.herokuapp.com/log", method: .post, parameters: ["log":locations.last?.description ?? "no location"]).validate().responseJSON(completionHandler: { (responce) in
                self.endBackgroundUpdateTask()
            })
        })


    }

Answer 1

如果应用程序处于后台状态，则获取UIBackgroundTaskIdentifier

 func scheduledLocationManager(_ manager: APScheduledLocationManager, didUpdateLocations locations: [CLLocation]) {

    print(locations.last?.description ?? "no location")

    // Get the background identifier if the app is in background mode
    if UIApplication.shared.applicationState == .background {
       backgroundUpdateTask = UIApplication.shared.beginBackgroundTask { [weak self] in
            if let strongSelf = self {
                UIApplication.shared.endBackgroundTask(strongSelf.backgroundUpdateTask)
                self.backgroundUpdateTask = UIBackgroundTaskInvalid
            }
        }
    }

    // Call the api to update the location to your server
    Alamofire.request("https://testomkar.herokuapp.com/log", method: .post, parameters: ["log":locations.last?.description ?? "no location"]).validate().responseJSON(completionHandler: { (responce) in

           //API completion block invalidate the identifier if it is not invalid already.
           if self.backgroundUpdateTask != nil && self.backgroundUpdateTask != UIBackgroundTaskInvalid {
                 UIApplication.shared.endBackgroundTask(backgroundUpdateTask)
                 self.backgroundUpdateTask = UIBackgroundTaskInvalid
           }
     })
}