iOS MapKit - 是否可以根据地图类型更改地图图钉?

iOS MapKit - Is it possible to change a map pin based on map type?

我找不到确切的问题。

我有一些在标准地图上看起来不错的自定义图钉。如果地图更改为 Satellite 或 Hybrid,我想使用其他图钉。

这可能吗?

到目前为止我已经试过了:

    annotationImageName = @"blackPin.png";

    if (segment == 1) {
        NSLog(@"segment 1");
        annotationImageName = @"whitePin.png";
    }
    else if (segment == 2) {
        NSLog(@"segment 2");
        annotationImageName = @"greyPin.png";
    }


}

......

MKAnnotationView *annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"annotationPin"];

annotationView.image = [UIImage imageNamed:annotationImageName];
 - (void) changeMapType: (id)sender
{
     annotationImageName = @"blackPin.png";

        if (mapView.mapType == MKMapTypeStandard)

         {

            mapView.mapType = MKMapTypeSatellite;
            NSLog(@"segment 1");
            annotationImageName = @"whitePin.png";
         } 
         else
          {
            mapView.mapType = MKMapTypeStandard;
            NSLog(@"segment 2");
           annotationImageName = @"greyPin.png";
          }

    } 

MKAnnotationView *annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"annotationPin"];

annotationView.image = [UIImage imageNamed:annotationImageName];

您可以创建自己的注释视图 class,当地图视图的 mapType 属性 发生变化时,您将 post 观察自定义通知:

@interface MyAnnotationView : MKAnnotationView
@property (nonatomic, strong) id<NSObject> observer;
@end

static NSString *kMapTypeChangeNotificationKey = @"com.domain.app.maptypechange";

@implementation MyAnnotationView

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self.observer];
}

- (instancetype)initWithAnnotation:(id<MKAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier mapType:(MKMapType)mapType {
    self = [super initWithAnnotation:annotation reuseIdentifier:reuseIdentifier];

    if (self) {
        [self updateImageBasedUponMapType:mapType];

        typeof(self) __weak weakSelf = self;
        self.observer = [[NSNotificationCenter defaultCenter] addObserverForName:kMapTypeChangeNotificationKey object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *note) {
            MKMapType mapType = [note.userInfo[@"mapType"] unsignedIntegerValue];
            [weakSelf updateImageBasedUponMapType:mapType];
        }];
    }

    return self;
}

- (void)updateImageBasedUponMapType:(MKMapType)mapType {
    if (mapType == MKMapTypeStandard) {
        self.image = [UIImage imageNamed:@"whitePin.png"];
    } else if (mapType == MKMapTypeSatellite) {
        self.image = [UIImage imageNamed:@"greyPin.png"];
    } else {
        NSLog(@"Unexpected mapType %lu", (unsigned long)mapType);
    }
}

@end

很明显,这意味着当您实例化它时,您必须向它传递一个对地图类型的引用:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
    if ([annotation isKindOfClass:[MKUserLocation class]]) { return nil; }

    static NSString *reuseIdentifier = @"MyCustomAnnotation";

    MyAnnotationView *annotationView = (id)[mapView dequeueReusableAnnotationViewWithIdentifier:reuseIdentifier];
    if (annotationView) {
        annotationView.annotation = annotation;
    } else {
        annotationView = [[MyAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseIdentifier mapType:mapView.mapType];
        annotationView.canShowCallout = true;
    }

    return annotationView;
}

现在,当您更新地图的 mapType 时,还会 post 这个自定义注释:

- (IBAction)changedValueSegmentControl:(UISegmentedControl *)sender {
    if (sender.selectedSegmentIndex == 0) {
        self.mapView.mapType = MKMapTypeStandard;
    } else if (sender.selectedSegmentIndex == 1) {
        self.mapView.mapType = MKMapTypeSatellite;
    }

    [[NSNotificationCenter defaultCenter] postNotificationName:kMapTypeChangeNotificationKey object:self userInfo:@{@"mapType" : @(self.mapView.mapType)}];
}