CLLocationManagerDelegate 클래스의 나침반 메서드를 통해 사용자가 이동하는 방향으로 이미지 회전

Question

나침반 메서드를 통해 이동하는 방향으로 자전거/자동차를 이동하고 싶습니다. 왜냐하면, 나는 didUpdateHeading 메서드를 사용했지만 여전히 사용자의 방향으로 자전거 이미지를 이동할 수 없습니다.

<pre> 
- (MKAnnotationView *)mapView:(MKMapView *)map viewForAnnotation:(id <MKAnnotation>)annotation 
{ 
    static NSString *AnnotationViewID = @"annotationViewID"; 
    annotationView = (MKAnnotationView *)[map dequeueReusableAnnotationViewWithIdentifier:AnnotationViewID]; 
    if (annotationView == nil) 
    { 
     annotationView = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationViewID] autorelease]; 
    }  
    annotationView.image = [UIImage imageNamed:@"Bike.png"]; 
    return annotationView; 
} 

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{ 
    currentLocation = newLocation; 
    previousLocation = oldLocation; 
    if(currentLocation != nil) 
    { 
     if (myAnnotation) 
     { 
      [self.myMapView removeAnnotation:myAnnotation]; 
     } 
     CLLocationCoordinate2D location = CLLocationCoordinate2DMake(currentLocation.coordinate.latitude, currentLocation.coordinate.longitude); 
     myAnnotation = [[MyAnnotation alloc] initWithCoordinates:location title:@"Current Location" subTitle:nil]; 
     [self.myMapView addAnnotation:myAnnotation]; 
    } 
} 
- (void)locationManager:(CLLocationManager*)manager didUpdateHeading:(CLHeading*)newHeading { 

    if (newHeading.headingAccuracy > 0) { 
     float heading = -1.0f * M_PI * newHeading.magneticHeading/180.0f; 
     annotationView.transform = CGAffineTransformMakeRotation(heading); 
    } 
} 
</pre> 

Answer 1

- (void)viewDidLoad 
{ 
    CLLocationManager *locationManager = [[CLLocationManager alloc] init]; 
    locationManager.delegate = self; 
    locationManager.desiredAccuracy = kCLLocationAccuracyKilometer; 

    [locationManager startUpdatingLocation]; 

    locationManager.headingFilter = kCLHeadingFilterNone; 
    [locationManager startUpdatingHeading]; 

    [self.view bringSubviewToFront:_compass_image]; 


    [super viewDidLoad]; 
    // Do any additional setup after loading the view from its nib. 
} 


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

    double rotation = newHeading.magneticHeading * 3.14159/180; 

    [_compass_image setTransform:CGAffineTransformMakeRotation(-rotation)]; 

}