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。

要在iOS 8中访问用户位置，你必须添加，

NSLocationAlwaysUsageDescription in the Info.plist 

这将询问用户获取其当前位置的权限。

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。

        // ** 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]);

}

- (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。

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];