Refresh MKAnnotationView on a MKMapView

Question

I'd like to a-synchronically load images for my custom MKAnnotationView; I'm already using the EGOImageView-framework (it goes very well with UITableViews), but I fail to make it work on MKMapView. Images seem to be loaded, but I cannot refresh them on the map - [myMap setNeedsDisplay] does nothing.

Answer 1

I haven't tried it myself, but it might work:
Get a view for annotation using MKMapView - (MKAnnotationView *)viewForAnnotation:(id <MKAnnotation>)annotation method and set new image to it.

Edit: Tried to do that myself and this approach worked fine for me:

//  Function where you got new image and want to set it to annotation view
for (MyAnnotationType* myAnnot in myAnnotationContainer){
 MKAnnotationView* aView = [mapView viewForAnnotation: myAnnot];
 aView.image = [UIImage imageNamed:@"myJustDownloadedImage.png"];
}

After calling this method all annotations images were updated.

Answer 2

I couldn't add a comment so i am usign the answer box -

What is the myAnnotationContainer in your code? is it the MKAnnotationViewContainer? How do you get that?

Answer 3

This is the only way I've found to force redraw of MKAnnotationViews:

// force update of map view (otherwise annotation views won't redraw)

CLLocationCoordinate2D center = mapView.centerCoordinate;

mapView.centerCoordinate = center;

Seems useless, but it works.