如何在iOS中获得仰角和磁场

Question

我试图在iOS中获得高程值和磁场值。我已经在谷歌上搜索了很长时间关于这些主题，但我找不到任何工作正常。

a)当我谈论仰角值时，我想要得到以度为单位的角度，当我移动手机的顶部时。我附上了一个图像，使它更容易。我一直在尝试这样做，但它不工作:

. h

#import <CoreMotion/CoreMotion.h>
@property (nonatomic, retain) CMMotionManager *motionManager;

m

self.motionManager = [[CMMotionManager alloc] init];
[self.motionManager startMagnetometerUpdates];
NSOperationQueue *myQueue = [[NSOperationQueue alloc] init];
[self.motionManager startDeviceMotionUpdatesToQueue:myQueue withHandler:^(CMDeviceMotion *motion, NSError *error){
    float degrees = (motion.attitude.roll*180) / M_PI;
    NSLog(@"Value of elevation is: %f", degrees);
}];

b)关于磁场，我想得到设备，磁铁，铁等影响我的手机精度的影响。*通过这种解决方案(在一类NSTimer中)获取的所有值都不正确:

NSLog(@"magnetometer data -> x: %f", self.motionManager.magnetometerData.magneticField.x);
NSLog(@"magnetometer data -> y: %f", self.motionManager.magnetometerData.magneticField.y);
NSLog(@"magnetometer data -> z: %f", self.motionManager.magnetometerData.magneticField.z);
float magneticField = sqrtf( powf(self.motionManager.magnetometerData.magneticField.x, 2) 
+ powf(self.motionManager.magnetometerData.magneticField.y, 2) + 
powf(self.motionManager.magnetometerData.magneticField.z, 2) );
NSLog(@"magneticField value: %@", magneticField.text);

有什么想法吗....谢谢

Answer 1

最后，我得到了两个问题的答案。这是我使用它的代码。希望对大家有所帮助。

磁场:. h

@property (nonatomic, retain) CLLocationManager *locationManager;

m

@synthesize locationManager;
- (void)viewDidLoad
{
[super viewDidLoad];
// Starting compass setup
if(locationManager == nil)
    locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.delegate = self;
//Start the compass updates.
if (CLLocationManager.headingAvailable) {
    [locationManager startUpdatingHeading];
    [locationManager startUpdatingLocation];
}
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];
}
}
-(void)locationManager:(CLLocationManager *) manager didUpdateHeading:(CLHeading *)newHeading
{
NSLog(@"Magnetic value: %@", [[NSString stringWithFormat:@"%.1f", sqrt(newHeading.x*newHeading.x + newHeading.y*newHeading.y + newHeading.z*newHeading.z)] stringByAppendingFormat:@" µT"]);
}

海拔高度:. h

@property (nonatomic, retain) CMMotionManager *motionManager;

m

@synthesize motionManager;
- (void)viewDidLoad
{
[super viewDidLoad];
// Initializating MotionManager Object    
motionManager = [[CMMotionManager alloc] init];
motionManager.showsDeviceMovementDisplay = YES;
motionManager.deviceMotionUpdateInterval = 20.0/60.0;
// Getting Elevation Value
CMDeviceMotionHandler  motionHandler = ^ (CMDeviceMotion *motion, NSError *error) {
    CMAttitude *a = motionManager.deviceMotion.attitude;
    NSLog(@"Elevation value, %@:", [[NSString stringWithFormat:@"%.0f", a.pitch*180/M_PI] stringByAppendingFormat:@"˚"]);
};
[motionManager startDeviceMotionUpdatesUsingReferenceFrame:CMAttitudeReferenceFrameXTrueNorthZVertical toQueue:[NSOperationQueue currentQueue] withHandler:motionHandler];
}

欢呼。