Seeing MKAnnotation Coordinates During Drag

问题

I want to be able to track the coordinates of my MKAnnotation as I drag it. Currently, I am only getting the coordinates as the drag begins.

I have tried implementing a custom MKAnnotationView subclass with touchesMoved, however this appears not to work. (As suggested here: Obtaining MKAnnotation's coordinate while dragging.)

By receiving the new coordinates as I drag my annotation, I will in turn be able to update my polygon shape.

回答1:

You can track the coordinates from MKAnnotationView.

When your view is dragged.The following delegate gets called.

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view didChangeDragState:(MKAnnotationViewDragState)newState fromOldState:(MKAnnotationViewDragState)oldState

In that you can use :

if (newState == MKAnnotationViewDragStateDragging) {
    CLLocationCoordinate2D location = [_polyMapView convertPoint:view.center toCoordinateFromView:view.superview];
}

Here _polyMapView would be your mapView and view would be your annotation view.This would get you the current coordinates of the Annotation.

来源：https://stackoverflow.com/questions/35048583/seeing-mkannotation-coordinates-during-drag