CODEWITHSUNDEEP
iosbackgroundnstimer
Jens
Jens

Reputation: 555

NSTimer does not fire in KILLED background

I've developed an iOS app that uses geofences in the background. When such event happens, I want to send an HTTP request. If that request fails, I want to retry it several times with some seconds of delay between the calls. I am using UIBackgroundMode for 'location' already.

My NSTimer scheduled looks like this:

dispatch_async(dispatch_get_main_queue(), ^{
      [NSTimer scheduledTimerWithTimeInterval:30.0 target:self selector:@selector(updateFence:) userInfo:fence repeats:NO];
});

This works fine in foreground and 'normal' background, but not if the app is killed and is started by iOS for a new geofence event. In that case the first http call works but when I then start the NSTimer with 30s delay it will never call the target selector.

Is there anything, beside UIBackgroundMode, that I need to use to be able to use NSTimer in (killed-) background? Am I scheduling the Timer on the wrong runloop/thread for that special background mode to work?

Upvotes: 0

Views: 119

Answers (1)

Daij-Djan
Daij-Djan

Reputation: 50139

when it is killed, it is killed. timers won't work - end of story - sorry

alternatives might be background app refreshes or silent pushes OR a user-visible local notification

Upvotes: 1

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