我当时在开发一款升级到iOS 8的应用，位置服务停止了。你可能会在Debug区域得到一个错误，如下所示:

试图启动MapKit位置更新而没有提示位置授权。必须先调用-[CLLocationManager requestWhenInUseAuthorization]或-[CLLocationManager requestAlwaysAuthorization]。

我做了侵入性最小的手术。首先添加NSLocationAlwaysUsageDescription条目到你的info.plist:

注意，我没有填写这个键的值。这仍然有效，我并不担心，因为这是一个内部应用程序。此外，已经有一个标题要求使用位置服务，所以我不想做任何多余的事情。

接下来我为iOS 8创建了一个条件:

if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
    [_locationManager requestAlwaysAuthorization];
}

之后locationManager:didChangeAuthorizationStatus:方法为call:

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:  (CLAuthorizationStatus)status
{
    [self gotoCurrenLocation];
}

现在一切正常。和往常一样，请查看文档。

对我来说，问题是CLLocationManagerDelegate类是私有的，这阻止了所有的委托方法被调用。我想这不是很常见的情况，但我想我应该提到它，以防它能帮助到任何人。

解决方案与向后兼容，不产生Xcode警告:

SEL requestSelector = NSSelectorFromString(@"requestWhenInUseAuthorization");
if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined &&
  [self.locationManager respondsToSelector:requestSelector]) {
((void (*)(id, SEL))[self.locationManager methodForSelector:requestSelector])(self.locationManager, requestSelector);
  [self.locationManager startUpdatingLocation];
} else {
  [self.locationManager startUpdatingLocation];
}

在Info.plist中设置NSLocationWhenInUseUsageDescription键。

对于iOS版本11.0+: 在Info.plist中设置NSLocationAlwaysAndWhenInUseUsageDescription键。还有另外2把钥匙。

- (void)viewDidLoad
{
    
    [super viewDidLoad];
    self.locationManager = [[CLLocationManager alloc] init];
    
    self.locationManager.delegate = self;
    if([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]){
        NSUInteger code = [CLLocationManager authorizationStatus];
        if (code == kCLAuthorizationStatusNotDetermined && ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)] || [self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)])) {
            // choose one request according to your business.
            if([[NSBundle mainBundle] objectForInfoDictionaryKey:@"NSLocationAlwaysUsageDescription"]){
                [self.locationManager requestAlwaysAuthorization];
            } else if([[NSBundle mainBundle] objectForInfoDictionaryKey:@"NSLocationWhenInUseUsageDescription"]) {
                [self.locationManager  requestWhenInUseAuthorization];
            } else {
                NSLog(@"Info.plist does not contain NSLocationAlwaysUsageDescription or NSLocationWhenInUseUsageDescription");
            }
        }
    }
    [self.locationManager startUpdatingLocation];
}

>  #pragma mark - CLLocationManagerDelegate

    - (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
    {
        NSLog(@"didFailWithError: %@", error);
        UIAlertView *errorAlert = [[UIAlertView alloc]
                                   initWithTitle:@"Error" message:@"Failed to Get Your Location" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [errorAlert show];
    }
    
    - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
    {
        NSLog(@"didUpdateToLocation: %@", newLocation);
        CLLocation *currentLocation = newLocation;
        
        if (currentLocation != nil) {
            longitudeLabel.text = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.longitude];
            latitudeLabel.text = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.latitude];
        }
    }

In iOS 8 you need to do two extra things to get location working: Add a key to your Info.plist and request authorization from the location manager asking it to start. There are two Info.plist keys for the new location authorization. One or both of these keys is required. If neither of the keys are there, you can call startUpdatingLocation but the location manager won’t actually start. It won’t send a failure message to the delegate either (since it never started, it can’t fail). It will also fail if you add one or both of the keys but forget to explicitly request authorization. So the first thing you need to do is to add one or both of the following keys to your Info.plist file:

NSLocationWhenInUseUsageDescription NSLocationAlwaysUsageDescription

这两个键都有一个字符串

这就是为什么你需要位置服务。你可以 输入一个字符串，如“位置是必须找到你在哪里” 和iOS 7一样，可以在InfoPlist中进行本地化。字符串文件。

对于那些使用Xamarin，我必须添加关键NSLocationWhenInUseUsageDescription的信息。手动plist，因为在Xamarin 5.5.3 Build 6或XCode 6.1的下拉列表中都不可用-只有NSLocationUsageDescription在列表中，这导致CLLocationManager继续无声地失败。

苹果的文件显示:

https://developer.apple.com/documentation/corelocation/requesting_permission_to_use_location_services https://developer.apple.com/documentation/corelocation/cllocationmanager/1620562-requestwheninuseauthorization

As of iOS 8, the presence of a NSLocationWhenInUseUsageDescription or a NSLocationAlwaysUsageDescription key value in your app's Info.plist file is required. It's then also necessary to request permission from the user prior to registering for location updates, either by calling [self.myLocationManager requestWhenInUseAuthorization] or [self.myLocationManager requestAlwaysAuthorization] depending on your need. The string you entered into the Info.plist will then be displayed in the ensuing dialog.

如果用户授予了权限，则业务照常进行。如果他们拒绝权限，则委托不会被告知位置更新。