Question

I know there was a question about this before. However, I think a little bit noob because I can’t get it solved.

I’m getting that error when trying this:

MKAnnotation *annotation = [[MKAnnotation alloc] initWithCoordinate:coordenada title:@"HELLO!"];
[mapa addAnnotation:annotation];

I also have the following method:

- (MKAnnotationView *) mapView: (MKMapView *) mapView viewForAnnotation: (id<MKAnnotation>) annotation
{
    MKPinAnnotationView *pin = (MKPinAnnotationView *) [self.mapa dequeueReusableAnnotationViewWithIdentifier: @"asdf"];
    if (pin == nil)
    {
        pin = [[[MKPinAnnotationView alloc] initWithAnnotation: annotation reuseIdentifier: @"asdf"] autorelease];
    }
    else
    {
        pin.annotation = annotation;
    }
    pin.pinColor = MKPinAnnotationColorRed;
    pin.animatesDrop = YES;
    return pin;
}

And did the #import < MapKit/MKAnnotation.h> in header.

Any help please?

Thank you very much!

Answer 1

MKAnnotation is a protocol, not a class that you can instantiate.

Have you defined your own class that implements MKAnnotation and a initWithCoordinate:title: method? If you have, use that class name and import its header file.

If you haven’t created your own annotation class, you’ll have to create one or you can use the pre-defined MKPointAnnotation class (in iOS 4+) instead:

MKPointAnnotation *annotation = [[MKPointAnnotation alloc] init];
annotation.coordinate = coordenada;
annotation.title = @"HELLO!";
[mapa addAnnotation:annotation];
[annotation release];

You’ll also need to do the following:

• add the MapKit framework to the project
• add #import <MapKit/MapKit.h> at the top of the file
• set the delegate property (or outlet in IB) of the map view otherwise viewForAnnotation won’t get called