How to refresh my iOS-App regularly?

Hi,

I tried to figure out how I can get my iOS-App to refresh regularly if it is in the background. I thought about WhatsApp. Even if it is closed it updates itself in the background and checks for new messages. But how does it do this?

I would like to observe the battery charging level. But my app should also observe it when I switched the screen off (locked my iPhone). I don't know how to do this. A Timer will not work, it is not available if the app is in the background. To clarify: I know how to read the battery level but I don't know how to observing the battery level when the app is in the background.

I tried to learn something about the Background App Refresh function but I had no success.

Have a read of iOS Background Execution Limits. It explains the basics.

I would like to observe the battery charging level.

AFAIK there’s no mechanism to resume (or relaunch) your app in the background when the battery charging level changes.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
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