Rotate MapView Based on accelerometer

Question

I am trying to rotate my MapView using CoreMotion around userLocation point. I'm successful in rotating the view but there is one problem: When the mapView is rotated the background white started showing. As shown in this picture (Ignore the red box below):
The code I'm using to accomplish this is:

- (void)viewDidLoad {
locationManager = [[CLLocationManager alloc] init];
    _mapView.delegate = self;
    locationManager.delegate = self;
[locationManager requestWhenInUseAuthorization];

    [locationManager startUpdatingLocation];

    _mapView.showsUserLocation = YES;
    [_mapView setMapType:MKMapTypeStandard];
    [_mapView setZoomEnabled:YES];
    [_mapView setScrollEnabled:YES];

 locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    locationManager.distanceFilter = kCLDistanceFilterNone;
    locationManager.headingFilter = 1;
    [locationManager startUpdatingHeading];

    motionManager = [[CMMotionManager alloc] init];
    motionManager.accelerometerUpdateInterval = 0.01;
    motionManager.gyroUpdateInterval = 0.01;

    [motionManager startAccelerometerUpdatesToQueue:[NSOperationQueue currentQueue]
                                        withHandler:^(CMAccelerometerData  *accelerometerData, NSError *error) {
                                            if (!error) {
                                                [self outputAccelertionData:accelerometerData.acceleration];
                                            }
                                            else{
                                                NSLog(@"%@", error);
                                            }
                                        }];

}

and for the heading

- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {

    //self.lblGrados.text = [NSString stringWithFormat:@"%.0f°", newHeading.magneticHeading];

    // Convert Degree to Radian and move the needle
    float newRad =  -newHeading.trueHeading * M_PI / 180.0f;

    [UIView animateWithDuration:0.6 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
        self.mapView.transform = CGAffineTransformMakeRotation(newRad);
    } completion:nil];
}

This method calls the one below:

- (void)outputAccelertionData:(CMAcceleration)acceleration{
    //UIInterfaceOrientation orientationNew;

    // Get the current device angle
    float xx = -acceleration.x;
    float yy = acceleration.y;
    float angle = atan2(yy, xx);
}

anf finally:

- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(userLocation.coordinate, 800.0f, 200.0f);
    //[self.mapView setRegion:[self.mapView regionThatFits:region] animated:YES];

    [self.mapView setCenterCoordinate:userLocation.location.coordinate animated:YES];
    [self.mapView setRegion:region animated:YES];
}
- (NSString *)deviceLocation {
    return [NSString stringWithFormat:@"latitude: %f longitude: %f", locationManager.location.coordinate.latitude, locationManager.location.coordinate.longitude];
}
- (NSString *)deviceLat {
    return [NSString stringWithFormat:@"%f", locationManager.location.coordinate.latitude];
}
- (NSString *)deviceLon {
    return [NSString stringWithFormat:@"%f", locationManager.location.coordinate.longitude];
}
- (NSString *)deviceAlt {
    return [NSString stringWithFormat:@"%f", locationManager.location.altitude];
}

So, what am I missing here? As far as I gone it has something to do with self.mapView.transform = CGAffineTransformMakeRotation(newRad); but I don't know what to change it to.

Answer 1

Try following code

[self.mapView setUserTrackingMode:MKUserTrackingModeFollowWithHeading animated:true];

It works