ios 方向检测代码

1，添加框架 CoreLocation.framework

2，在ViewController.h中写如下代码

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>

@interface ViewController : UIViewController<CLLocationManagerDelegate>
{
    CLLocationManager * _locationManger;
}
@property (retain, nonatomic) IBOutlet UILabel *header;

@end

 3，ViewController.m代码如下：

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.
    
    _locationManger = [[CLLocationManager alloc]init];
    
    if([CLLocationManager headingAvailable]){
        _locationManger.headingFilter = 0.1 ;//设置精度，当度数改变0.1度后通知
        [_locationManger startUpdatingHeading];
        
    }
}
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
    if(newHeading.headingAccuracy>0){
        CLLocationDirection theHeding = newHeading.magneticHeading;
        _header.text = [NSString stringWithFormat:@"%lf度",theHeding];
    
    }  
}