How to count number and which annotations shown on MapView, when zooming?

Question

I need to count number of annotations when i zooming mapView, and get array with which are shown on map, and then, i need to reload my Table and show list of only which shown on map.

How can i get number and array with annotation?

Answer 1

How about these two methods from MapKit class:

1) Get visible rectangle of map using:

@property(nonatomic, readonly) CGRect annotationVisibleRect

http://developer.apple.com/library/ios/DOCUMENTATION/MapKit/Reference/MKMapView_Class/MKMapView/MKMapView.html#//apple_ref/occ/instp/MKMapView/annotationVisibleRect

2) Then get annotation NSSet from parameter map rectangle:

- (NSSet *)annotationsInMapRect:(MKMapRect)mapRect

http://developer.apple.com/library/ios/DOCUMENTATION/MapKit/Reference/MKMapView_Class/MKMapView/MKMapView.html#//apple_ref/occ/instm/MKMapView/annotationsInMapRect:

So I would expect something like this:

-(void)getAnotationsInVisibleMapRectangle
{
    NSSet *annotationSet = [myMapView annotationsInMapRect:myMapView.annotationVisibleRect];

    // print number of annotations
    NSLog(@"Number of annotations in rect: %d", annotationSet.count);

    // this will return an array from the NSSet
    NSArray *annotationArray = [annotationSet allObjects]; 
}

Does that help?