iphone - MapView MKAnnotation が MKMapView でコールアウトを表示しない

Question

マップ ビューにいくつかのマップ ピンを表示しています。注釈に触れたときに吹き出しが表示されない理由がわかりません。これが私のコードです。カテゴリ ID に応じて異なるピン画像を表示するために、viewDidLoad メソッドにいくつかの条件付きコードがあります。カスタム ピンは正しく表示されますが、それらに触れても何も起こりません。

これを手伝ってくれてありがとう。

- (void)viewDidLoad {

   [super viewDidLoad];

    [self requestData];

    CLLocationCoordinate2D centerCoord = CLLocationCoordinate2DMake(44.2632, 11.4403);

    MKCoordinateSpan span;
    span.latitudeDelta=5;
    span.longitudeDelta=5;

    MKCoordinateRegion ITRegion = MKCoordinateRegionMake(centerCoord, span);
    ITRegion.span=span;

    [mapView setRegion: ITRegion animated: YES];

    mapView.delegate=self;

    [self.mapView setShowsUserLocation:YES];


    for (int i=0; i<[publicDataArray count]; i++) {
        MKPointAnnotation* annotation= [MKPointAnnotation new];

        CLLocationCoordinate2D coordinate;
        coordinate.latitude = [[[[publicDataArray objectAtIndex:i] objectForKey:@"address"] objectForKey:@"lat"] doubleValue];
        coordinate.longitude = [[[[publicDataArray objectAtIndex:i] objectForKey:@"address"] objectForKey:@"lng"] doubleValue];

        NSString *catId = [NSString stringWithFormat:@"%@",[[publicDataArray objectAtIndex:i] objectForKey:@"category_id"]];

        if ([catId isEqual: @"213"]) {
            annView.image = [UIImage imageNamed:@"comprareMap.png"];//sets image for pin

        } else if ([catId isEqual:@"217"]) {

            annView.image = [UIImage imageNamed:@"vedereMap.png"];//sets image for pin

        } else if ([catId isEqual:@"221"]) {

            annView.image = [UIImage imageNamed:@"mangiareMap.png"];//sets image for pin

        }
        annotation.coordinate = coordinate;


        [mapView addAnnotation: annotation];

    }
}

- (MKAnnotationView *) mapView:(MKMapView *)mapingView viewForAnnotation:(id <MKAnnotation>) annotation {
    annView = nil;
    if(annotation != mapingView.userLocation)
    {

        static NSString *defaultPinID = @"";
        annView = (MKAnnotationView *)[mapingView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
        if ( annView == nil )
            annView = [[MKAnnotationView alloc]
                       initWithAnnotation:annotation reuseIdentifier:defaultPinID] ;


        UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        [rightButton setTitle:annotation.title forState:UIControlStateNormal];
        [rightButton addTarget:self
                        action:@selector(showDetails:)
              forControlEvents:UIControlEventTouchUpInside];
        annView.rightCalloutAccessoryView = rightButton;

        annView.canShowCallout = YES;


    }
    return annView;
}