// ** Don't forget to add NSLocationWhenInUseUsageDescription in MyApp-Info.plist and give it a string

        self.locationManager = [[CLLocationManager alloc] init];
        self.locationManager.delegate = self;
        // Check for iOS 8. Without this guard the code will crash with "unknown selector" on iOS 7.
        if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
            [self.locationManager requestWhenInUseAuthorization];
        }
        [self.locationManager startUpdatingLocation];


    // Location Manager Delegate Methods    
    - (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
    {
        NSLog(@"%@", [locations lastObject]);

}

为了确保这与iOS 7向后兼容，你应该检查用户运行的是iOS 8还是iOS 7。例如:

#define IS_OS_8_OR_LATER ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)

//In ViewDidLoad
if(IS_OS_8_OR_LATER) {
   [self.locationManager requestAlwaysAuthorization];
}

[self.locationManager startUpdatingLocation];

- (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。

Swift开发者常犯的一个错误:

首先确保你添加了一个值到plist为NSLocationWhenInUseUsageDescription或NSLocationAlwaysUsageDescription。

如果你仍然没有看到一个窗口弹出要求授权，看看你是否把行var locationManager = CLLocationManager()在你的视图控制器的viewDidLoad方法。如果这样做，那么即使调用locationManager.requestWhenInUseAuthorization()，也不会显示任何内容。这是因为在viewDidLoad执行后，locationManager变量被释放(清除)。

解决方案是在类方法的顶部找到var locationManager = CLLocationManager()行。

在iOS 8中，你需要做两件额外的事情来让定位工作:给你的信息添加一个键。Plist并从位置管理器请求授权，要求它启动

info.plist:

<key>NSLocationUsageDescription</key>
<string>I need location</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>I need location</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>I need location</string>

将此添加到代码中

if (IS_OS_8_OR_LATER)
{
    [locationmanager requestWhenInUseAuthorization];

    [locationmanager requestAlwaysAuthorization];
}

添加关键NSLocationWhenInUseUsageDescription或NSLocationAlwaysUsageDescription(后台GPS使用)字符串要求使用GPS在每个信息。Plist从每个目标。 通过运行命令获得许可: (自我initLocationManager: locationManager);

其中“initLocationManager”为:

// asks for GPS authorization on iOS 8
-(void) initLocationManager:(CLLocationManager *) locationManager{

    locationManager = [[CLLocationManager alloc]init];

    if([locationManager respondsToSelector:@selector(requestAlwaysAuthorization)])
        [locationManager requestAlwaysAuthorization];
}

记住，如果键不是在每个信息上。Plist为每个目标，应用程序将不会询问用户。if提供了与iOS 7的兼容性，respondsToSelector:方法保证了未来的兼容性，而不仅仅是解决iOS 7和8的问题。