iBeacon monitoring/ranging after device restarts

Question

I built a simple ios app with IBeacon, when the app is in foreground or background it works ok but after rebooting my phone, my app stops getting CoreLocation delegate callbacks. This is my AppDelegate.m code.

#import "AppDelegate.h"
#import <CoreLocation/CoreLocation.h>
#import "ViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

   if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]) {
        [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeSound
                                                                                                              categories:nil]];
    }


    if(launchOptions != nil){
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alerta"
                                                        message:[launchOptions[UIApplicationLaunchOptionsLocalNotificationKey] description]
                                                       delegate:nil
                                              cancelButtonTitle:@"OK"
                                              otherButtonTitles:nil];
        [alert show];
    }


    NSUUID *beaconUUID = [[NSUUID alloc] initWithUUIDString:@"B39ED98FF-2900-441A-802F-9C398FC199D2"];
    NSString *regionIdentifier = @"iBeacons region 1";
    CLBeaconRegion *beaconRegion = [[CLBeaconRegion alloc] initWithProximityUUID: beaconUUID identifier: regionIdentifier ];
    beaconRegion.notifyEntryStateOnDisplay = YES;
    self.locationManager = [[CLLocationManager alloc]init];



    if([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]){
        [self.locationManager requestAlwaysAuthorization];
    }

    self.locationManager.delegate = self;
    //self.locationManager.pausesLocationUpdatesAutomatically = NO;

    [self.locationManager startMonitoringForRegion:beaconRegion];
    [self.locationManager startRangingBeaconsInRegion:beaconRegion];
    [self.locationManager startUpdatingLocation];


    return YES;
}

-(void)sendLocalNotificationWithMessage:(NSString*)message {
    UILocalNotification *notification = [[UILocalNotification alloc] init];
    notification.alertBody = message;
    [[UIApplication sharedApplication] scheduleLocalNotification:notification];
}


- (void) locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLBeaconRegion *)region{

    ViewController *viewController = (ViewController*) self.window.rootViewController;
    viewController.beacons = beacons;
    [viewController.tableView reloadData];

    NSString *message = @"";

    if(beacons.count > 0){
        CLBeacon *nearestBeacon = beacons.firstObject;
        if(nearestBeacon.proximity == self.lastProximity || nearestBeacon.proximity == CLProximityUnknown){
            return;
        }
        self.lastProximity = nearestBeacon.proximity;

        switch (nearestBeacon.proximity) {
            case CLProximityFar:
                message = @"CLProximityFar";
                break;
            case CLProximityNear:
                message= @"CLProximityNear";
                break;
            case CLProximityImmediate:
                message= @"CLProximityImmediate";
                break;
            case CLProximityUnknown:
                return;
      }

    }else {
        message = @"No BEACONS";
    }

    NSLog(@"%@", message);
    [self sendLocalNotificationWithMessage:message];

}

- (void) locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region{
    [manager startRangingBeaconsInRegion:(CLBeaconRegion*) region];
    [self.locationManager startUpdatingLocation];

    NSLog(@"INSIDE REGION");
    [self sendLocalNotificationWithMessage:@"INSIDE REGION"];
}

- (void) locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region{
    [manager stopRangingBeaconsInRegion:(CLBeaconRegion*) region];
   [self.locationManager stopUpdatingLocation];

    NSLog(@"OUTSIDE REGION");
    [self sendLocalNotificationWithMessage:@"OUTSIDE REGION"];
}

- (void)locationManager:(CLLocationManager *)manager didDetermineState:(CLRegionState)state forRegion:(CLRegion *)region{

    if (state == CLRegionStateInside) {


        //Start Ranging
        [manager startRangingBeaconsInRegion:(CLBeaconRegion*) region];
        [self.locationManager startUpdatingLocation];

        NSLog(@"INSIDE REGION");
        [self sendLocalNotificationWithMessage:@"INSIDE REGION"];
    }

    else{

        //Stop Ranging
        [manager stopRangingBeaconsInRegion:(CLBeaconRegion*) region];
        [self.locationManager stopUpdatingLocation];

        NSLog(@"OUTSIDE REGION");
        [self sendLocalNotificationWithMessage:@"OUTSIDE REGION"];
    }

}


-(void)application:(UIApplication *)application didReceiveLocalNotification:(NSDictionary *)userInfo {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"ALERT"
                                                    message:@"didReceiveLocalNotification"
                                                   delegate:nil
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];


}

- (void)applicationWillResignActive:(UIApplication *)application {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

- (void)applicationWillEnterForeground:(UIApplication *)application {
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

- (void)applicationDidBecomeActive:(UIApplication *)application {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

- (void)applicationWillTerminate:(UIApplication *)application {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

@end

I cant find what is the issue, i need your help!

Answer 1

The code looks OK. When testing this, I would recommend you do the following:

1. Launch your app
2. Turn on your beacon
3. Verify you get a didEnterRegion callback.
4. Turn off your beacon
5. Verify you get a didExitRegion callback.
6. Reboot your phone
7. Wait at least 2 minutes (it takes a bit of time before CoreLocation fully starts up after reboot.)
8. Turn on your beacon
9. Wait a few minutes to see if you get a didEnterRegion callback.