Question

I am displaying different annotation points in a mapview. I want to display different titles and subtitles for all the different annotations. I have my viewForAnnotation delegate method implemented in the below manner.

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation;
{
    NSLog(@"annotation Class %@", [annotation class]);

if ([annotation isKindOfClass:[HGMovingAnnotation class]]) {

    static NSString *kMovingAnnotationViewId = @"HGMovingAnnotationView";

    HGMovingAnnotationView *annotationView = (HGMovingAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:kMovingAnnotationViewId];

    if (!annotationView) {
        annotationView = [[HGMovingAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:kMovingAnnotationViewId];
    }

    //configure the annotation view
    annotationView.image = [UIImage imageNamed:@"symbol-moving-annotation.png"];

    annotationView.bounds = CGRectMake(0, 0, 20, 20); //initial bounds (default)
    annotationView.mapView = mapView;

    NSLog(@"Inside Moving Annotation");
    return annotationView;
}

static NSString *kCustomAnnotationView = @"CustomAnnotationView";

MKPinAnnotationView* customPinView = [[MKPinAnnotationView alloc]initWithAnnotation:annotation reuseIdentifier:kCustomAnnotationView];

if ([annotation isKindOfClass:[CLLocation class]]) {
    MKAnnotationView *customAnnotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation
                                                                          reuseIdentifier:kCustomAnnotationView];
    customAnnotationView.image = [UIImage imageNamed:@"customAnnotation"];

    customAnnotationView.canShowCallout = NO;
    customAnnotationView.centerOffset = CGPointMake(2,-12);
    NSLog(@"Inside Custom Annotation1");
    return customAnnotationView;
} else {
    customPinView.annotation = annotation;
    customPinView.pinColor = MKPinAnnotationColorPurple;
    NSLog(@"Inside Custom Annotation2");
    return customPinView;
}

}

I want to display the title and subTitle for the customPinView Annotations. Please help me.

Answer 1

Annotation views do not have a title or subtitle. You need to subclass MKAnnotation and set the (sub)title on the custom annotation. The viewForAnnotation method is not the right place for this, you should call [annotation setTitle:@"my title"] right before [mapView addAnnotation:annotation].

Sample code:

@interface MyCustomAnnotation : NSObject <MKAnnotation> {

@property (nonatomic, copy) NSString *title;
@property (nonatomic, copy) NSString *subtitle;
@property (nonatomic) CLLocationCoordinate2D coordinate;

@end