I've noticed that if I use MKMapView's selectAnnotation:animated:
, that it will scroll my map off screen if the MKAnnotation is not displayed in the current MKCoordinateRegion that my map is displaying.
Is there a trivial way to check if an annotation is currently on screen within the specified MKCoordinateRegion? I'd like to be able to select an annotation that's only on screen and not something offscreen.
Use the annotationsInMapRect:
method in the MKMapView
class. It returns a NSSet
of all annotation objects that are visible in the given map rect. Use the containsObject:
method of NSSet
to test if the annotation is present in that set of visible annotations.
MKMapRect visibleMapRect = aMapView.visibleMapRect;
NSSet *visibleAnnotations = [aMapView annotationsInMapRect:visibleMapRect];
BOOL annotationIsVisible = [visibleAnnotations containsObject:someAnnotation];
Also visibleMapRect
is same as the region but just a different form of representation. Take from the docs,
visibleMapRect
The area currently displayed by the map view.
@property(nonatomic) MKMapRect visibleMapRect
This property represents the same basic information as the region property but specified as a map rectangle instead of a region.