Hide, show annotation on MkMapView

问题:

How to hide annotation when zooming out the map view. I have a big number of annotation i have to hide them because if the region displayed on the map is too big you can see only the annotations.

回答1:

To do this, you have to check the size of your region, and depending of it you set the views hidden or not.

I tested the code bellow but, you will probably need some adjustments.

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated
{
    NSArray *annotations = [_mapView annotations];  
    MyAnnotation *annotation = nil; 
    for (int i=0; i<[annotations count]; i++)
    {
        annotation = (MyAnnotation*)[annotations objectAtIndex:i];
        if (_mapView.region.span.latitudeDelta > .010)
        {
            [[_mapView viewForAnnotation:annotation] setHidden:YES];
        }
        else {
            [[_mapView viewForAnnotation:annotation] setHidden:NO];
        }
    }
}

Cheers,
VFN

回答2:

Swift version:

let annotations = self.maps.annotations

    for annotation in annotations
    {
        if (self.maps.region.span.latitudeDelta > 0.010)
        {

            self.maps.viewForAnnotation(annotation)?.hidden = true

        }
        else {

            self.maps.viewForAnnotation(annotation)?.hidden = false

        }
    }