这是我的目标:每次他打开具有 MapView 的视图然后停止位置以节省电池时,我都必须在地图上显示用户位置和他的地址。到目前为止我可以做到,但如果用户移动到另一个区域并进入视图(离开后),位置不会改变。
这是我的代码:
- (void)viewDidLoad
{
mapView.mapType = MKMapTypeStandard;
self.locationManager.delegate = self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[super viewDidLoad];
}
- (void)viewDidAppear:(BOOL)animated{
if(!self.locationManager){
self.locationManager = [[CLLocationManager alloc] init];
}
[self.locationManager startUpdatingLocation];
}
-(void)viewDidDisappear:(BOOL)animated{
self.locationManager = nil;
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
MKCoordinateRegion viewRegion =
MKCoordinateRegionMakeWithDistance(newLocation.coordinate, 2000, 2000);
MKCoordinateRegion adjustedRegion = [mapView regionThatFits:viewRegion];
[mapView setRegion:adjustedRegion animated:YES];
[manager stopUpdatingLocation];
MKReverseGeocoder *geocoder = [[MKReverseGeocoder alloc]
initWithCoordinate:newLocation.coordinate];
geocoder.delegate = self;
[geocoder start];
}
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark {
MapLocation *annotation = [[MapLocation alloc] init];
annotation.streetAddress = placemark.thoroughfare;
annotation.city = placemark.locality;
annotation.state = placemark.administrativeArea;
annotation.zip = placemark.postalCode;
annotation.coordinate = geocoder.coordinate;
[mapView addAnnotation:annotation];
geocoder.delegate = nil;
}
- (void)openCallout:(id<MKAnnotation>)annotation {
[mapView selectAnnotation:annotation animated:YES];
}
- (MKAnnotationView *) mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>) annotation {
static NSString *placemarkIdentifier = @"Map Location Identifier";
if ([annotation isKindOfClass:[MapLocation class]]) {
MKPinAnnotationView *annotationView = (MKPinAnnotationView *)[theMapView dequeueReusableAnnotationViewWithIdentifier:placemarkIdentifier];
if (annotationView == nil) {
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:placemarkIdentifier];
}
else{
annotationView.annotation = annotation;
}
annotationView.enabled = YES;
annotationView.canShowCallout = YES;
annotationView.image = [UIImage imageNamed:@"rescue"];
[self performSelector:@selector(openCallout:) withObject:annotation afterDelay:0.5];
return annotationView;
}
return nil;
}
我在另一个视图上有一个 CLLocationManager,它可以在没有地图的情况下获取用户位置(这里的位置工作得很好)。如果在该视图上开始位置并返回带有地图的视图,则它会更新。为什么?
有什么想法吗?