Handling large quantity of MKMapView Annotations

Question

I have a map view with a large quantity of annotations (3000+), when the user is zoomed to a reasonable level all is well and fast.

Although when the user zooms out and

Answer 1

As I understand your code, you are hiding all the annotations' views if the mapView is zoomed out more than a certain specified value.

It seems to me that something more like the following would be better:

- (void)mapView: (MKMapView*)_mapView regionDidChangeAnimated: (BOOL)animated
{
    if (_mapView.region.span.latitudeDelta > .010 && self.mapViewsHidden == NO) {
        for (MapAnnotation* annotation in _mapView.annotations) {
            [[_mapView viewForAnnotation: annotation] setHidden: YES];
        }
        [self.warningLabel setHidden: NO];
        [self setMapViewsHidden: YES];
    }
    else if (_mapView.region.span.latitudeDelta <= .010 && self.mapViewsHidden == YES) {
        for (MapAnnotation* annotation in _mapView.annotations) {
            [[_mapView viewForAnnotation: annotation] setHidden: NO];
        }
        [self.warningLabel setHidden: YES];
        [self setMapViewsHidden: NO];
    }
}

With the above, in most cases the only thing this code does is a couple of if checks.

Another solution would be to remove the annotations when they shouldn't show on the map. Personally, I think this would be better, that way the code doesn't have to create views for annotations that haven't been shown on the map yet.