Objectivec CLLocationManager startUpdatingLocation 未调用 locationManager：didUpdateLocations： 或 locationManager：didFailWithError：

我试图在iOS项目中使用CLLocationManager框架来访问用户的位置，但当我打电话时

[locationManager startUpdatingLocation]

locationManager:didUpdateLocations:和locationManager:didFailWithError:都没有接到电话.

//myViewController.h
@interface myViewController : UITableViewController <CLLocationManagerDelegate>
@end

//myViewController.m
@implementation myViewController{
    CLLocationManager *locationManager;
}

//edit
- (void)viewDidLoad
{
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
}
//finish edit

-(void)getLocation
{
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)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 didUpdateLocations:(NSArray *)locations
{
    CLLocation *newLocation = locations[[locations count] -1];
    CLLocation *currentLocation = newLocation;
    NSString *longitude = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.longitude];
    NSString *latitude = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.latitude];

if (currentLocation != nil) {
   NSLog(@"latitude: %@", latitude);
   NSLog(@"longitude: @"%@", longitude);
}else {
    UIAlertView *errorAlert = [[UIAlertView alloc]
                               initWithTitle:@"Error" message:@"Failed to Get Your Location" 
                                                     delegate:nil 
                                            cancelButtonTitle:@"OK" 
                                            otherButtonTitles:nil];
    [errorAlert show];
}

}
@end

不管文档中怎么说，都不会调用委托方法:

"此方法立即返回.调用此方法会导致位置管理器获得初始位置修复(可能需要几秒钟)，并通过调用其locationManager:didUpdateLocations:方法[…]通知您的代理."除了实现locationManager:didUpdateLocations:方法的委托对象之外，它还应该实现locationManager:didFailWithError:方法来响应潜在的错误."

不知道如何调试这个问题.

谢谢

青年成就组织