-[CLLocationManager requestWhenInUseAuthorization]或-[CLLocationManager requestAlwaysAuthorization]错误

Question

这是我的代码，显示了地图上当前位置的警报和蓝点：

MapName.h

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
#import <CoreLocation/CoreLocation.h>


@interface MapName : UIViewController <MKMapViewDelegate, CLLocationManagerDelegate>

@property (strong, nonatomic) IBOutlet MKMapView *MapName;
@property (strong, nonatomic) CLLocationManager *locationManager;

@end

MapName.m

- (void)viewDidLoad
{
[super viewDidLoad];

self.locationManager = [[CLLocationManager alloc]init];
self.locationManager.delegate = self;
if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
    [self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];

//Center the map
[self gotoLocation];

//Show current position
_MapName.showsUserLocation = YES;

}

我已经将键NSLocationWhenIsUseUsageDescription作为字符串添加到Info.plist中。我在Xcode上仍然会遇到同样的错误。

Answer 1

其原因是：

[self.locationManager startUpdatingLocation];

和

_MapName.showsUserLocation = YES;

在调用这些文件之前，您需要检查用户是否已授予权限。还要确保关闭故事板上的MKMapKit中的用户位置(这一次花了我几天的时间追踪)。

做以下事情：

CLAuthorizationStatus authorizationStatus= [CLLocationManager authorizationStatus];

if (authorizationStatus == kCLAuthorizationStatusAuthorized ||
    authorizationStatus == kCLAuthorizationStatusAuthorizedAlways ||
    authorizationStatus == kCLAuthorizationStatusAuthorizedWhenInUse) {

    [self.locationManager startUpdatingLocation];       
    _MapName.showsUserLocation = YES;        

}

根据您的应用程序，您可能不想要求用户的许可启动，因为这是不推荐的。

Answer 2

错误消息是非常字面的。在获得授权之前，不要调用[self.locationManager startUpdatingLocation]。根据文档，您的[self.locationManager requestWhenInUseAuthorization]是异步的。

当当前授权状态为kCLAuthorizationStatusNotDetermined时，此方法异步运行，并提示用户授予应用程序使用位置服务的权限。

这意味着，您既提示进行访问，又同时启动扫描。

相反，尝试实现-[CLLocationManagerDelegate locationManager:didChangeAuthorizationStatus:]并在确定有授权后在那里启动扫描。

Answer 3

关于迅捷的：

  let locationManager: CLLocationManager = CLLocationManager()
  let authorizationStatus = CLLocationManager.authorizationStatus()


  override func viewDidLoad() {
    super.viewDidLoad()
    if(authorizationStatus == .AuthorizedWhenInUse || authorizationStatus == .AuthorizedAlways) {
       locationManager.startUpdatingLocation()
    }
    else
    {
      locationManager.requestWhenInUseAuthorization()
    }
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters

}

不要忘记将以下键添加到Info.plist文件中：

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