实现MKMapViewDelegate但未调用MKMapViewDelegate方法的类的子类化

Question

我是subClassing，一个实现了MKMapViewDelegate.I的类，也在超类中设置了委托，但是我的-(MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation方法没有被调用。以下是我的代码

我的superClass代码

 //  RecentPhotosMapViewController.h
 @interface RecentPhotosMapViewController : UIViewController <MKMapViewDelegate>

     @property (nonatomic,strong) NSArray *annotations;
     @property(nonatomic,weak) IBOutlet MKMapView *mapView;

@end


 //  RecentPhotosMapViewController.m
- (void)viewDidLoad{

      [super viewDidLoad];
// Do any additional setup after loading the view.

    // load annotation data



       self.mapView.delegate = self;
}

  - (MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:    (id<MKAnnotation>)annotation{

MKAnnotationView *aView = [mapView dequeueReusableAnnotationViewWithIdentifier:@"MapVC"];

     // safety code
     if(!aView){
         aView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"MapVC"];
         aView.canShowCallout = YES;
         aView.leftCalloutAccessoryView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 30, 30)];
         aView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];

      }
     aView.annotation = annotation;
    [(UIImageView *)aView.leftCalloutAccessoryView setImage:nil];

    return aView;
}

我的子类代码

     //  RecentPhotosMapViewControllerWithAnnotationData.h
     @interface RecentPhotosMapViewControllerWithAnnotationData : RecentPhotosMapViewController
     @end

RecentPhotosMapViewControllerWithAnnotationData.m文件

      -(void) viewDidLoad{


// extract annotation data.....
// set zoom level


[super viewDidLoad];

}

然而，-(void) mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view method is called

任何帮助我们都将不胜感激

Answer 1

尝试将[super viewDidLoad];作为子类中viewDidLoad的第一行。

当您调用设置委托的[super viewDidLoad]时，一切都已经发生了。

Answer 2

将mapView委托赋值行保留为派生类viewDidLoad方法的最后一行：

RecentPhotosMapViewControllerWithAnnotationData.m

-(void) viewDidLoad
{

// extract annotation data.....
// set zoom level

[super viewDidLoad];

self.mapView.delegate = self;

}