定位 - CoreLocation - 指南针

#import "ViewController.h"

#import <CoreLocation/CoreLocation.h>

@interface ViewController ()<CLLocationManagerDelegate>

// 定位管理对象

@property (nonatomic, strong) CLLocationManager *mgr;

// 指南针

@property (nonatomic, strong) UIImageView *compass;

@end

@implementation ViewController

- (CLLocationManager *)mgr{

if (!_mgr) {

_mgr = [[CLLocationManager alloc] init];

}

return _mgr;

}

- (void)viewDidLoad {

[super viewDidLoad];

// 1. 添加指南针

UIImageView *iv = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bg_compasspointer"]];

iv.center = CGPointMake(self.view.center.x, self.view.center.y);

[self.view addSubview:iv];

self.compass = iv;

// 2. 成为代理

self.mgr.delegate = self;

// 3. 开始监听

// 开始获取用户方向  --- 不需要授权

//    [self.mgr startUpdatingHeading];

}

// 授权状态改变调用这个方法

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status

{

if (status == kCLAuthorizationStatusNotDetermined) {

LogYellow(@"正在授权");

}else if ((status == kCLAuthorizationStatusAuthorizedAlways) || (status == kCLAuthorizationStatusAuthorizedWhenInUse)){

[self.mgr startUpdatingHeading];

}else{

LogYellow(@"授权失败");

}

}

#pragma mark - CLLocationManagerDelegate

// 当获取到用的的方向时, 就会调用

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

{

/**

magneticHeading 设备与磁北的相对角度

trueHeading 设置与真北的相对角度, 必须和定位一起使用, iOS需要设置的位置来计算真北

真北始终指向地理北极点

磁北对应随着时间变化的地球磁场北极

*/

LogRed(@"%f",newHeading.magneticHeading);

// 1.角度转换成弧度

CGFloat angle = newHeading.magneticHeading * M_PI/ 180.0;

// 2.旋转图片

/**

*  顺时针: 正数

*  逆时针: 负数

*/

//    self.compass.transform = CGAffineTransformIdentity;

self.compass.transform = CGAffineTransformMakeRotation(-angle);

}