如何在颤振中注册应用程序侦听器以进行互联网连接事件？

Question

I have an app flutter that runs in Android and iOS.

This app is used in areas without any internet connection. When the user arrives at some place with internet connection, all the offline data must be sent to the servers.

Have an background task running and checking in loop for internet connections, or even a recurrent scheduled task, is not an option because:

• The moment between the use of the app in the field and the moment that the user will be in place with internet connection might take many hours.
• Running threads in background will consume resources and draw the mobile battery.
• Android/iOS might finish the background process and the data not be sent unless the user open the app.

I'm wondering how to register a kind of listener, listening for "internet connectivity events" broadcasted by operating system when they happen and that will awake my app and trigger callback.

Then, I don't have to keep an unnecessary background task running infinitely but I can still do the job when the mobile get connected in the internet, even having my app closed/sleeping.

How can I do it in flutter ?

Answer 1

There's a package that listens to connectivity status called connectivity_plus , you can subscribe to a stream like so:

    import 'package:connectivity_plus/connectivity_plus.dart';

@override
initState() {
  super.initState();

  subscription = Connectivity().onConnectivityChanged.listen((ConnectivityResult result) {
    // Got a new connectivity status!
  })
}

// Be sure to cancel subscription after you are done
@override
dispose() {
  super.dispose();

  subscription.cancel();
}

However in the documentation, it states clearly that connectivity changes are no longer communicated to Android apps in the background starting with Android O. You should always check for connectivity status when your app is resumed. The broadcast is only useful when your application is in the foreground.

You might wanna research that and see if it's possible to do so in the background. Here's a similar question which might help you out

Answer 2

You can try background task and add a delay of your choice. That should work. Please check this link. https://pub.dev/packages/flt_worker_nullsafety