#import <UIKit/UIKit.h>

#import <CoreLocation/CoreLocation.h>

@interface ViewController : UIViewController<CLLocationManagerDelegate>

@property (retain, nonatomic) UIImageView *compassImageView;

@property (retain, nonatomic) CLLocationManager *locationManager;

@end

ViewController.m代码如下：

- (void)viewDidLoad

{

    [super viewDidLoad];

    UIImageView* backgroundImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"BackGroundPad.png"]];

    [self.view addSubview:backgroundImage];

    //创建指南针图片

    self.compassImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"Compass_HD.png"]];

    self.compassImageView.center = CGPointMake(370, 500);

    [self.view addSubview:self.compassImageView];

    //初始化locationManager并设置代理类

    self.locationManager = [[CLLocationManager alloc]init];

    self.locationManager.delegate = self;

	if ([CLLocationManager headingAvailable]) {

        //设置精度

        self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;

        //设置滤波器不工作

        self.locationManager.headingFilter = kCLHeadingFilterNone;

        //开始更新

        [self.locationManager startUpdatingHeading];

    }

    else

    {

        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"atention" message:@"compass not Available" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles: nil];

        [alert show];

    }

}

//调用locationManager成员方法

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

{

    //重置view的位置

    self.compassImageView.transform = CGAffineTransformIdentity;

    CGAffineTransform transform = CGAffineTransformMakeRotation(-1 * M_PI*newHeading.magneticHeading/180.0);

    self.compassImageView.transform = transform;

}

这样就OK啦 ！ 要在真机上测试哦！！！