问MKMapView中userLocation的中心区域

EN

- (void)viewDidLoad {
    mainDelegate = (PublicArtOmahaAppDelegate*)[[UIApplication sharedApplication]delegate]; 

    XMLController  *myXMLController = [[XMLController alloc] init]; 
    [myXMLController parse];
    mapView.showsUserLocation = YES;
    [self gotoLocation];

    // add annotations to map
    [self.mapView addAnnotations:mainDelegate.mapAnnotations];
    [myXMLController release];
}

- (void)gotoLocation
{
    MKCoordinateRegion newRegion;

    CLLocation *userLocation = mapView.userLocation.location;
    float latitude = userLocation.coordinate.latitude;
    float longitude = userLocation.coordinate.latitude;
    newRegion.center.latitude = latitude;
    newRegion.center.longitude = longitude;

    [self.mapView setRegion:newRegion animated:YES];
}