MKMapView add annotation and remove it after some time

Question

I have a MKMapView and I add some annotations to it. I want to remove annotations one by one after some time that it was added. I need that every annotation have its own lifespan. Is it possible? How should I achieve that?

Answer 1

Your best choice is to use -(void)removeAnnotations:(NSArray *)annotations from your MKMapView.

Just save your annotation somewhere, for example a NSDictionary with {date : annotationObject}, and retrieve it when you want to delete.

For example:

//Call somewhere to delete after 2 seconds
[self performSelector:@selector(deleteAnnotation:) withObject:annotation afterDelay:2.f]

//this function will remove the annotation from your map
-(void) deleteAnnotation:(id) object{
    [self.map removeAnnotations:@[object]];
}

Answer 2

MKMapView has removeAnnotation and removeAnnotations methods which remove already added annotations.

If you want each annotation to have their own lifespan :

• Create AnnotationLifespanDelegate protocol with method for indicating end of life which takes the annotation as a parameter (e.g. func dearAnnotationRIP(annotation : MKAnnotation)).

• Create a custom MKAnnotation with the lifespan and lifeSpanDelegate properties and a startCountdown method.

• startCountdown method simply starts a timer with with an interval equal to the lifespan and calls the end of life method on the delegate.

• Implement AnnotationLifespanDelegate methods in view controller and while creating annotation objects, make sure you set the lifespan and the delegate and call the startCountdown method on the annotation immediately after you add it to the map view.

• In the annotation end of life method, remove annotation from the map.