How Do i relaunch my iOS app from Kill state for long task?

Question

First i will explain what i want to achieve. I have a BLE lock. i want that my application will wake up from kill state and start scanning BLE device. Once the BLE device found it will connect with my phone and get unlock.

All this is working in background mode and i tested this many times. but i also want this to be work when app is in kill state.

I tried several things. First I tried Geofencing but in case of geofencing app wake up for less time i'm not properly scan the BLE device. When didEnterRegion region: called i sent the local notification and it was working fine. So after that i tried to scan BLE Devices when didEnterRegion region: and also get the notification that scan is started but i think after some time app remove from the background automatically and could not relaunch. So that's why i'm failed to discovered any BLE device.

I also read apple document for Core BlueTooth: https://developer.apple.com/library/archive/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html

There is mention that how to perform long task like open and close door lock but isn't help me.

Please guide me how to do this when app is in kill state.

Thanks for the help :)

UPDATE: What i mean from kill state is suspended/ terminated/removed from background. I just want that once user get enter into the region of geofence then app launch in background and scanning for the BLE device started. so after that i want app will stay into the background until door get unlock.

Answer 1

As Paulw11 mentioned, there's no way to relaunch an app in the background once it is terminated/killed by the user. Apple have done this deliberately for security and functionality reasons: if a user deliberately kills an app because it is buggy/faulty, the app should not be able to relaunch itself.

More information can be found here:-

• Core Bluetooth Background Processing for iOS Apps
• BLE device keep connect with iPhone when application terminate

I hope this helps.