所有代码都运行良好，但不能提供所需的结果。方向针不会移动到完美的位置。有时候它有效，有时候不行。
func DegreesToRadians (value:Double) -> Double {
return value * M_PI / 180.0
}
func RadiansToDegrees (value:Double) -> Double {
return value * 180.0 / M_PI
}
class ViewController: UIViewController , CLLocationManagerDelegate {
var needleAngle : Double?
//Main Composs
@IBOutlet weak var composs: UIImageView!
//Needle Move with respect to compose
@IBOutlet weak var needle: UIImageView!
@IBOutlet weak var mapView: MKMapView!
// Kabhalocation
var kabahLocation : CLLocation?
var latitude : Double?
var longitude : Double?
var distanceFromKabah : Double?
let locationManger = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
//KabhaLocation Hardcoded.
kabahLocation = CLLocation(latitude: 21.42 , longitude: 39.83)
//Delegate
self.locationManger.delegate = self
self.locationManger.desiredAccuracy = kCLLocationAccuracyBest
if #available(iOS 8.0, *) {
self.locationManger.requestAlwaysAuthorization()
} else {
// Fallback on earlier versions
}
self.locationManger.startUpdatingLocation()
self.locationManger.startUpdatingHeading()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// Mark: - LocationManger Delegate
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let location = locations.last
let center = CLLocationCoordinate2D(latitude: (location?.coordinate.latitude)!, longitude: (location?.coordinate.longitude)!)
print("current location latitude \((location?.coordinate.latitude)!) and longitude \((location?.coordinate.longitude)!)")
self.latitude = location?.coordinate.latitude
self.longitude = location?.coordinate.longitude
//
// self.latitude = 31.5497
// self.longitude = 74.3436
self.locationManger.startUpdatingLocation()
needleAngle = self.setLatLonForDistanceAndAngle(location!)
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
print("Error " + error.localizedDescription)
}
func setLatLonForDistanceAndAngle(userlocation: CLLocation) -> Double
{
let lat1 = DegreesToRadians(userlocation.coordinate.latitude)
let lon1 = DegreesToRadians(userlocation.coordinate.longitude)
let lat2 = DegreesToRadians(kabahLocation!.coordinate.latitude)
let lon2 = DegreesToRadians(kabahLocation!.coordinate.longitude)
distanceFromKabah = userlocation.distanceFromLocation(kabahLocation!)
let dLon = lon2 - lon1;
let y = sin(dLon) * cos(lat2)
let x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dLon)
var radiansBearing = atan2(y, x)
if(radiansBearing < 0.0)
{
radiansBearing += 2*M_PI;
}
// print("Initial Bearing \(radiansBearing*180/M_PI)")
let distanceFromKabahUnit = 0.0
return radiansBearing
}
func locationManager(manager: CLLocationManager, didUpdateHeading newHeading: CLHeading) {
let needleDirection = -newHeading.trueHeading;
let compassDirection = -newHeading.magneticHeading;
self.needle.transform = CGAffineTransformMakeRotation(CGFloat(((Double(needleDirection) ) / 180.0) + needleAngle!))
print("Needle \(CGAffineTransformMakeRotation(CGFloat(((Double(needleDirection) ) / 180.0) + needleAngle!)))")
self.composs.transform = CGAffineTransformMakeRotation(CGFloat((Double(compassDirection) ) / 180.0))
print("composs \(CGAffineTransformMakeRotation(CGFloat((Double(compassDirection) ) / 180.0)))")
}
override func viewDidAppear(animated: Bool) {
needleAngle = 0.0
self.locationManger.startUpdatingHeading()
kabahLocation = CLLocation(latitude: 21.42 , longitude: 39.83)
self.locationManger.delegate = self
}
override func viewDidDisappear(animated: Bool) {
self.locationManger.delegate = nil
}
答案 0 :(得分：10)
实际上你在这里做错了的是让指南针在 didLocationChange 方法中旋转。实际上你需要根据地球的真北来进行旋转，为此你需要使用 didUpdateLocationHeader 。这会根据地球的真实北方给你读数。我在下面发布我的代码。您还可以在我的github
上找到完整的工作项目import UIKit
import CoreLocation
class ViewController: UIViewController ,CLLocationManagerDelegate{
@IBOutlet weak var ivCompassBack: UIImageView!
@IBOutlet weak var ivCompassNeedle: UIImageView!
let latOfKabah = 21.4225
let lngOfKabah = 39.8262
var location: CLLocation?
let locationManager = CLLocationManager()
var bearingOfKabah = Double()
override func viewDidLoad() {
super.viewDidLoad()
initManager()
}
func initManager(){
locationManager.requestAlwaysAuthorization()
locationManager.requestWhenInUseAuthorization()
if CLLocationManager.locationServicesEnabled() {
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
locationManager.startUpdatingLocation()
locationManager.startUpdatingHeading()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateHeading heading: CLHeading) {
let north = -1 * heading.magneticHeading * Double.pi/180
let directionOfKabah = bearingOfKabah * Double.pi/180 + north
ivCompassBack.transform = CGAffineTransform(rotationAngle: CGFloat(north));
ivCompassNeedle.transform = CGAffineTransform(rotationAngle: CGFloat(directionOfKabah));
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let newLocation = locations.last!
location = newLocation
bearingOfKabah = getBearingBetweenTwoPoints1(location!, latitudeOfKabah: self.latOfKabah, longitudeOfKabah: self.lngOfKabah) //calculating the bearing of KABAH
}
func degreesToRadians(_ degrees: Double) -> Double { return degrees * Double.pi / 180.0 }
func radiansToDegrees(_ radians: Double) -> Double { return radians * 180.0 / Double.pi }
func getBearingBetweenTwoPoints1(_ point1 : CLLocation, latitudeOfKabah : Double , longitudeOfKabah :Double) -> Double {
let lat1 = degreesToRadians(point1.coordinate.latitude)
let lon1 = degreesToRadians(point1.coordinate.longitude)
let lat2 = degreesToRadians(latitudeOfKabah);
let lon2 = degreesToRadians(longitudeOfKabah);
let dLon = lon2 - lon1;
let y = sin(dLon) * cos(lat2);
let x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dLon);
var radiansBearing = atan2(y, x);
if(radiansBearing < 0.0){
radiansBearing += 2 * Double.pi;
}
return radiansToDegrees(radiansBearing)
}
}
答案 1 :(得分：4)
//
// ViewController.swift
// CurrentLocation
//
// Created by Muhammad Rizwan Anjum on 26/8/16.
// Copyright © 2016 Muhammad Rizwan Anjum. All rights reserved.
//
import UIKit
import MapKit
import CoreLocation
func DegreesToRadians (value:Double) -> Double {
return value * M_PI / 180.0
}
func RadiansToDegrees (value:Double) -> Double {
return value * 180.0 / M_PI
}
class ViewController: UIViewController , CLLocationManagerDelegate {
var needleAngle : Double?
@IBOutlet weak var composs: UIImageView!
@IBOutlet weak var needle: UIImageView!
@IBOutlet weak var mapView: MKMapView!
var kabahLocation : CLLocation?
var latitude : Double?
var longitude : Double?
var distanceFromKabah : Double?
let locationManger = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
kabahLocation = CLLocation(latitude: 21.42 , longitude: 39.83)
self.locationManger.delegate = self
self.locationManger.desiredAccuracy = kCLLocationAccuracyBest
if #available(iOS 8.0, *) {
self.locationManger.requestAlwaysAuthorization()
} else {
// Fallback on earlier versions
}
self.locationManger.startUpdatingLocation()
self.locationManger.startUpdatingHeading()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// Mark: - LocationManger Delegate
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let location = locations.last
// let center = CLLocationCoordinate2D(latitude: (location?.coordinate.latitude)!, longitude: (location?.coordinate.longitude)!)
print("current location latitude \((location?.coordinate.latitude)!) and longitude \((location?.coordinate.longitude)!)")
self.latitude = location?.coordinate.latitude
self.longitude = location?.coordinate.longitude
//
// self.latitude = 31.5497
// self.longitude = 74.3436
self.locationManger.startUpdatingLocation()
needleAngle = self.setLatLonForDistanceAndAngle(location!)
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
print("Error " + error.localizedDescription)
}
func setLatLonForDistanceAndAngle(userlocation: CLLocation) -> Double
{
let lat1 = DegreesToRadians(userlocation.coordinate.latitude)
let lon1 = DegreesToRadians(userlocation.coordinate.longitude)
let lat2 = DegreesToRadians(kabahLocation!.coordinate.latitude)
let lon2 = DegreesToRadians(kabahLocation!.coordinate.longitude)
distanceFromKabah = userlocation.distanceFromLocation(kabahLocation!)
let dLon = lon2 - lon1;
let y = sin(dLon) * cos(lat2)
let x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dLon)
var radiansBearing = atan2(y, x)
if(radiansBearing < 0.0)
{
radiansBearing += 2*M_PI;
}
// print("Initial Bearing \(radiansBearing*180/M_PI)")
let distanceFromKabahUnit = 0.0
return radiansBearing
}
func locationManager(manager: CLLocationManager, didUpdateHeading newHeading: CLHeading) {
let needleDirection = -newHeading.trueHeading;
let compassDirection = -newHeading.magneticHeading;
//you Need to Multiply With M_PI
self.needle.transform = CGAffineTransformMakeRotation(CGFloat(((Double(needleDirection) * M_PI) / 180.0) + needleAngle!))
print("Needle \(CGAffineTransformMakeRotation(CGFloat(((Double(needleDirection) * M_PI) / 180.0) + needleAngle!)))")
self.composs.transform = CGAffineTransformMakeRotation(CGFloat((Double(compassDirection) * M_PI) / 180.0))
print("composs \(CGAffineTransformMakeRotation(CGFloat((Double(compassDirection) * M_PI) / 180.0)))")
}
override func viewDidAppear(animated: Bool) {
needleAngle = 0.0
self.locationManger.startUpdatingHeading()
kabahLocation = CLLocation(latitude: 21.42 , longitude: 39.83)
self.locationManger.delegate = self
}
override func viewDidDisappear(animated: Bool) {
self.locationManger.delegate = nil
}
}