问为什么它找不到我的信标？

EN

    - (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;
    [self initRegion];
    [self locationManager:self.locationManager didStartMonitoringForRegion:self.beaconRegion];
}

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
    [self.locationManager startRangingBeaconsInRegion:self.beaconRegion];
}

- (void)initRegion {
    NSUUID *uuid = [[NSUUID alloc] initWithUUIDString:BEACONUUID];
    self.beaconRegion = [[CLBeaconRegion alloc] initWithProximityUUID:uuid identifier:BEACONIDENTIFIER];
    [self.locationManager startMonitoringForRegion:self.beaconRegion];

}

- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region {
    NSLog(@"Beacon Found");
    [self.locationManager startRangingBeaconsInRegion:self.beaconRegion];
}

-(void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region {
    NSLog(@"Left Region");
    [self.locationManager stopRangingBeaconsInRegion:self.beaconRegion];
    self.beaconFoundLabel.text = @"No";
}

-(void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLBeaconRegion *)region {
    CLBeacon *beacon = [beacons lastObject];//<== is always 0

    self.beaconFoundLabel.text = @"Yes";
    self.proximityUUIDLabel.text = beacon.proximityUUID.UUIDString;
    self.majorLabel.text = [NSString stringWithFormat:@"%@", beacon.major];
    self.minorLabel.text = [NSString stringWithFormat:@"%@", beacon.minor];
    self.accuracyLabel.text = [NSString stringWithFormat:@"%f", beacon.accuracy];
    if (beacon.proximity == CLProximityUnknown) {
        self.distanceLabel.text = @"Unknown Proximity";
    } else if (beacon.proximity == CLProximityImmediate) {
        self.distanceLabel.text = @"Immediate";
    } else if (beacon.proximity == CLProximityNear) {
        self.distanceLabel.text = @"Near";
    } else if (beacon.proximity == CLProximityFar) {
        self.distanceLabel.text = @"Far";
    }
    self.rssiLabel.text = [NSString stringWithFormat:@"%ld", (long)beacon.rssi];
}