CODEWITHSUNDEEP
iosswiftcore-location
jimmy2times
jimmy2times

Reputation: 33

Magnetic Heading sample code for iOS

Can anyone provide me with a short snippet that will return me the magnetic heading of the iPhone? I do not want Objective-C please. I need it in Swift.

I have written these lines so far but it does not return me any value:

let locManager = CLLocationManager()
locManager.desiredAccuracy = kCLLocationAccuracyBest
locManager.requestWhenInUseAuthorization()
locManager.startUpdatingLocation()

locManager.startUpdatingHeading()
locManager.headingOrientation = .portrait
locManager.headingFilter = kCLHeadingFilterNone

print(locManager.heading?.trueHeading.binade as Any)

Thanks!

Upvotes: 3

Views: 1982

Answers (1)

Code Different
Code Different

Reputation: 93161

You didn't set the delegate for the location manager. iOS does not update your location right away. Rather, it will call a function provided by your delegate when it has a location / heading update. The reason behind this setup is efficiency. Instead of 10 apps having 10 different location managers competing for time on the GPS hardware, these 10 location managers will request to be notified when the GPS has an update.

Try this:

class ViewController: UIViewController, CLLocationManagerDelegate {
    @IBOutlet weak var label: UILabel!
    var locManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()

        locManager.desiredAccuracy = kCLLocationAccuracyBest
        locManager.requestWhenInUseAuthorization()
        locManager.headingOrientation = .portrait
        locManager.headingFilter = kCLHeadingFilterNone
        locManager.delegate = self // you forgot to set the delegate

        locManager.startUpdatingLocation()
        locManager.startUpdatingHeading()
    }

    // MARK: -
    // MARK: CLLocationManagerDelegate
    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print("Location Manager failed: \(error)")
    }

    // Heading readings tend to be widely inaccurate until the system has calibrated itself
    // Return true here allows iOS to show a calibration view when iOS wants to improve itself
    func locationManagerShouldDisplayHeadingCalibration(_ manager: CLLocationManager) -> Bool {
        return true
    }

    // This function will be called whenever your heading is updated. Since you asked for best
    // accuracy, this function will be called a lot of times. Better make it very efficient
    func locationManager(_ manager: CLLocationManager, didUpdateHeading newHeading: CLHeading) {
        label.text = "\(newHeading.magneticHeading)"
    }
}

Upvotes: 5

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