Objective-c：如何从位置服务中查找航向（方向）？

Question

我正在研究位置服务，并希望从位置服务获取标题，我拥有所有所需的属性，例如纬度、经度等，但我也想找到方向（标题），

 (void)locationUpdate:(CLLocation *)location {
    locationLable.text = [location description];
    CLLocationCoordinate2D coordinate = [location coordinate];
    NSLog(@"This is location   %@",[location description]);
    NSLog(@"Lattitude          =   %@",[NSString stringWithFormat:@"%f", coordinate.latitude]);
    NSLog(@"Langitude          =   %@",[NSString stringWithFormat:@"%f", coordinate.longitude]);
    NSLog(@"Altitude           =   %@",[NSString stringWithFormat:@"%gm", location.altitude]);
    NSLog(@"horizontalAccuracy =   %@",[NSString stringWithFormat:@"%gm", location.horizontalAccuracy]);
    NSLog(@"verticalAccuracy   =   %@",[NSString stringWithFormat:@"%gm", location.verticalAccuracy]);
    NSLog(@"Speed   =   %@",[NSString stringWithFormat:@"%gm", location.speed]);

}


- (void)headingUpdate:(CLHeading *)heading {
    NSLog(@"This is heading   %@",[heading description]);

}

- (void)viewDidLoad {
    locationController = [[MyCLController alloc] init];
    locationController.delegate = self;
    [locationController.locationManager startUpdatingLocation];
    [locationController.locationManager startUpdatingHeading];
}

我找到了一些线索可以从 CLHeading 获取它，但仍然无法从中获取它CL 标题。我正在使用上面的代码

Answer 1

阅读 http://developer.apple.com /library/ios/#DOCUMENTATION/CoreLocation/Reference/CLHeading_Class/Reference/Reference.html :)
我想你应该使用 trueHeading，我想..

真实标题

相对于正北的航向（以度为单位）。 （只读）
@property（只读，非原子）CLLocationDirection trueHeading