从后台URLSession发布中获取响应

Question

I'm executing a post that could take a few seconds to come back and what to enable background mode. I'm trying to figure out if the app goes into the background while waiting on the post to return can I get the response somehow?

let bgSessionConfig = URLSessionConfiguration.background(withIdentifier: identifier)
bgSessionConfig.sharedContainerIdentifier = "myid"
backgroundSessionManager = SessionManager(configuration: bgSessionConfig)

So basically will the completionHandler below ever get called if in the background?

sessionManager.request(url, method: .post, parameters: dataParameters, encoding: parameterEncoding, headers: finalHeaders)
            .validate()
            .responseJSON(queue: self.dispatchQueue, completionHandler: {response in

func application(_ application: UIApplication, handleEventsForBackgroundURLSession identifier: String, completionHandler: @escaping () -> Void) { }

Answer 1

The completion handler in handleEventsForBackgroundURLSession is not something that "gets called". It is something that you must call when urlSessionDidFinishEvents arrives. What "gets called" is handleEvents itself. Your job here is to specify the background URL session (possibly creating it if you were just launched) and make yourself its delegate, immediately. That is how you will be contacted, through the normal delegate messages.

You would have received certain delegate messages if this had not been a background session; well, now you will receive those delegate messages when this is a background session.