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嗨，我在这种情况下需要有关 ios 中标题数据的帮助，我正在我的应用程序中使用 AI 使用 CoreLocation 框架作为我
的 .h 文件

@interface ViewController : UIViewController<CLLocationManagerDelegate>{
    UIImageView *arrowImage; 
    UILabel *magneticHeadingLabel; 
    UILabel *trueHeadingLabel;
    CLLocationManager *locationManager;
}

@property (nonatomic, retain) CLLocationManager *locationManager;
@end

在 .m 文件中

@implementation ViewController
@synthesize locationManager;

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

    NSLog(@"New magnetic heading: %f", newHeading.magneticHeading);
    NSLog(@"New true heading: %f", newHeading.trueHeading);
    NSLog(@"=>%@",[NSString stringWithFormat:@"%.1fmi",newHeading.headingAccuracy]);
    NSString *headingstring = [[NSString alloc] initWithFormat:@"%f",newHeading.trueHeading];
    trueHeadingLabel.text = headingstring;
    [headingstring release];

    NSString *magneticstring = [[NSString alloc]initWithFormat:@"%f",newHeading.magneticHeading];
    magneticHeadingLabel.text = magneticstring;
    [magneticstring release];

}

-(void)getHeadInfo{
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    self.locationManager.delegate = self;

    if ([CLLocationManager headingAvailable] ) 
    {      
        NSLog(@"Heading Available...!");
        self.locationManager.headingFilter = kCLHeadingFilterNone; 
        [self.locationManager startUpdatingHeading];

    } 
    else {
        NSLog(@"No Heading Available: ");
        UIAlertView *noCompassAlert = [[UIAlertView alloc] initWithTitle:@"No Compass!" message:@"This device does not have the ability to measure magnetic fields." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [noCompassAlert show];
        [noCompassAlert release];
    } 
}

- (void)viewDidLoad {
    [super viewDidLoad];
    arrowImage = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"right_arrow"]];
    arrowImage.frame = CGRectMake(95, 30, 128, 128);
    [self.view addSubview:arrowImage];

    trueHeadingLabel = [[UILabel alloc] initWithFrame:CGRectMake(15, 300, 250, 30)];
    trueHeadingLabel.textAlignment = UITextAlignmentLeft;
    trueHeadingLabel.textColor = [UIColor purpleColor];
    trueHeadingLabel.backgroundColor = [UIColor clearColor];
    trueHeadingLabel.font = [UIFont systemFontOfSize:13];
    trueHeadingLabel.text = [NSString stringWithFormat:@"trueHeadingLabel:"];
    [self.view addSubview:trueHeadingLabel];

    magneticHeadingLabel = [[UILabel alloc] initWithFrame:CGRectMake(15, 350, 250, 30)];
    magneticHeadingLabel.textAlignment = UITextAlignmentLeft;
    magneticHeadingLabel.textColor = [UIColor purpleColor];
    magneticHeadingLabel.backgroundColor = [UIColor clearColor];
    magneticHeadingLabel.font = [UIFont systemFontOfSize:13];
    magneticHeadingLabel.text = [NSString stringWithFormat:@"magneticHeadingLabel:"];
    [self.view addSubview:magneticHeadingLabel];

    UIButton *start = [[UIButton alloc]initWithFrame:CGRectMake(140, 310, 50, 30)];
    [start setBackgroundColor:[UIColor redColor]];
    [start setTitle:@"start" forState:UIControlStateNormal];
    [start addTarget:self action:@selector(getHeadInfo) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:start];
    [start release];
}

问题是我知道模拟器没有返回航向数据，我使用的是 ipod touch，但 [CLLocationManager headingAvailable] 仍然没有返回 true。这是一种紧急情况，请帮助任何人

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1 回答 1

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我不太确定，但据我所知，iPod touch 不包含 GPS / 指南针模块。它通过 wifi 数据库获取其位置信息。因此，您不会获得标题，因为 iPod Touch 无法将其提供给您。

iPod Touch“只有”一个陀螺仪和一个加速度计可用。要读取有关这些的信息，您必须使用Core Motion Framework

CMMotionManager 对象是 iOS 提供的运动服务的网关。这些服务为应用程序提供加速度计数据、旋转速率数据、磁力计数据和其他设备运动数据，例如姿态。这些类型的数据源自设备的加速度计和（在某些型号上）其磁力计和陀螺仪。

于 2012-07-02T06:09:35.683 回答