Estou tentando implementar as sugestões dadas emesta postagem.

Infelizmente os passos não estão claros para mim. Eu tentei implementar essas sugestões, mas o backgroundTimeRemaining continua a diminuir mesmo depois de eu iniciar e parar o locationServices. Foi assim que eu desenvolvi:

<code>- (void)applicationDidEnterBackground:(UIApplication *)application {

    UIApplication*    app = [UIApplication sharedApplication];

    bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
        [app endBackgroundTask:bgTask];
        bgTask = UIBackgroundTaskInvalid;
    }];

    // Start the long-running task and return immediately.
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        // Do the work associated with the task.
        self.timer = nil;
        [self initTimer];

    });
}
</code>

initTimer:

<code>- (void)initTimer {

    // Create the location manager if this object does not
    // already have one.
    if (nil == self.locationManager)
        self.locationManager = [[CLLocationManager alloc] init];

    self.locationManager.delegate = self;
    [self.locationManager startMonitoringSignificantLocationChanges];

    if (self.timer == nil) {
        self.timer = [NSTimer scheduledTimerWithTimeInterval:0.3
                                              target:self
                                            selector:@selector(checkUpdates:)
                                            userInfo:nil
                                             repeats:YES];
    }
}
</code>

verificar atualizações:

<code>- (void)checkUpdates:(NSTimer *)timer{
    UIApplication*    app = [UIApplication sharedApplication];
    double remaining = app.backgroundTimeRemaining;
    if(remaining < 580.0) {
        [self.locationManager startUpdatingLocation]; 
        [self.locationManager stopUpdatingLocation]; 
        [self.locationManager startMonitoringSignificantLocationChanges];
    }
    DbgLog(@"Reminaing %f", app.backgroundTimeRemaining);
}
</code>

Alguém tem uma sugestão sobre o que pode estar errado no meu código? Ambos initTimer e checkUpdates estão sendo chamados, mas somente durante o tempo de execução em segundo plano (+ - 10 Mins). Eu quero o aplicativo para atualizar o local a cada n minutos "para sempre".

O UIBackgroundModes do meu aplicativo está definido para o local.

ATUALIZAR:

Agora estou redefinindo o cronômetro em didUpdateToLocation e didFailWithError. Mas ainda assim o backgroundTimeRemaining continua diminuindo:

<code>- (void)locationManager:(CLLocationManager *)manager 
didUpdateToLocation:(CLLocation *)newLocation 
       fromLocation:(CLLocation *)oldLocation {

NSLog(@"Did Update Location = %f / %f", [newLocation coordinate].latitude, [newLocation coordinate].longitude);

UIApplication*    app = [UIApplication sharedApplication];

bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
    [app endBackgroundTask:bgTask];
    bgTask = UIBackgroundTaskInvalid;
}];

// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

    // Do the work associated with the task.

    [self initTimer];

});
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {

[self.locationManager stopUpdatingLocation]; 
UIApplication*    app = [UIApplication sharedApplication];

bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
    [app endBackgroundTask:bgTask];
    bgTask = UIBackgroundTaskInvalid;
}];

// Start the long-running task and return immediately.
[self initTimer];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

    // Do the work associated with the task.

});

}
</code>

Eu também estou invalidando o temporizador:

<code>- (void)checkUpdates:(NSTimer *)timer{
UIApplication*    app = [UIApplication sharedApplication];
double remaining = app.backgroundTimeRemaining;
if(remaining < 580.0 && remaining > 570.0) {
    [self.timer invalidate];
    self.timer = nil;
    [self.locationManager startUpdatingLocation]; 
    [self.locationManager stopUpdatingLocation]; 
}
DbgLog(@"*************************Checking for updates!!!!!!!!!!! Reminaing %f", app.backgroundTimeRemaining);
}
</code>