使用GPS在iOS中定位

示意图如下：

LBS.H

@property (weak, nonatomic) IBOutletUITextField *latitudeField;
@property (weak, nonatomic) IBOutletUITextField *longitudeField;
@property (weak, nonatomic) IBOutletUITextField *accuracyField;
@property (nonatomic) CLLocationManager *lm;

LBS.M

- (void)viewDidLoad
{
    [superviewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
    lm = [[CLLocationManageralloc] init];
    if ([lmlocationServicesEnabled]) {
        lm.delegate = self;
        lm.desiredAccuracy = kCLLocationAccuracyBest;
        lm.distanceFilter = 1000.0f;
        [lmstartUpdatingLocation];
    }
}


(void) locationManager: (CLLocationManager *) manager
   didUpdateToLocation: (CLLocation *) newLocation
      fromLocation: (CLLocation *) oldLocation{
  NSString *lat = [[NSStringalloc] initWithFormat:@”%g”,
               newLocation.coordinate.latitude];
  self.latitudeField.text = lat;
  NSString *lng = [[NSStringalloc] initWithFormat:@”%g”,
               newLocation.coordinate.longitude];
  self.longitudeField.text = lng;
  NSString *acc = [[NSStringalloc] initWithFormat:@”%g”,
               newLocation.horizontalAccuracy];
  self.accuracyField.text = acc;


}

(void) locationManager: (CLLocationManager *) manager
  didFailWithError: (NSError *) error {
  NSString *msg = @”Error obtaining location”;
  UIAlertView *alert = [[UIAlertViewalloc]
                    initWithTitle:@”Error”
                    message:msg
                    delegate:nil
                    cancelButtonTitle: @”Done”
                    otherButtonTitles:nil];
  [alert show];
}

mapviewer.m

(void)viewDidAppear:(BOOL)animated
{
  MKCoordinateSpan span;
  span.latitudeDelta=.009;
  span.longitudeDelta=.009;
  MKCoordinateRegion region;
  CLLocation *newLocation = ((NaviViewController *)self.parentViewController).location;
  region.center = newLocation.coordinate;
  region.span=span;
  [self.mapView setRegion:region animated:TRUE];
  self.mapView.showsUserLocation = YES;


}