Detect screen on/off from iOS service

Question

I am developing a network monitor app that runs in background as a service. Is it possible to get a notification/call when the screen is turned on or off?

It exists

Answer 1

Using the lower-level notify API you can query the lockstate when a notification is received:

#import 

int notify_token;
notify_register_dispatch("com.apple.springboard.lockstate", ¬ify_token, dispatch_get_main_queue(), ^(int token) {
    uint64_t state = UINT64_MAX;
    notify_get_state(token, &state);
    NSLog(@"com.apple.springboard.lockstate = %llu", state);
});

Of course your app will have to start a UIBackgroundTask in order to get the notifications, which limits the usefulness of this technique due to the limited runtime allowed by iOS.