let ann = MKPointAnnotation()
self.ann.coordinate = annLoc
self.ann.title = "Customize me"
self.ann.subtitle = "???"
self.mapView.addAnnotation(ann)

func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
    if annotation is MKUserLocation {
        return nil
    }

    let identifier = "MyCustomAnnotation"

    var annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier(identifier)
    if annotationView == nil {
        annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
        annotationView?.canShowCallout = true
    } else {
        annotationView!.annotation = annotation
    }

    configureDetailView(annotationView!)

    return annotationView
}

func configureDetailView(annotationView: MKAnnotationView) {
    let width = 300
    let height = 200

    let snapshotView = UIView()
    let views = ["snapshotView": snapshotView]
    snapshotView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[snapshotView(300)]", options: [], metrics: nil, views: views))
    snapshotView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:[snapshotView(200)]", options: [], metrics: nil, views: views))

    let options = MKMapSnapshotOptions()
    options.size = CGSize(width: width, height: height)
    options.mapType = .SatelliteFlyover
    options.camera = MKMapCamera(lookingAtCenterCoordinate: annotationView.annotation!.coordinate, fromDistance: 250, pitch: 65, heading: 0)

    let snapshotter = MKMapSnapshotter(options: options)
    snapshotter.startWithCompletionHandler { snapshot, error in
        if snapshot != nil {
            let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: width, height: height))
            imageView.image = snapshot!.image
            snapshotView.addSubview(imageView)
        }
    }

    annotationView.detailCalloutAccessoryView = snapshotView
}

func mapView(mapView: MKMapView, didSelectAnnotationView view: MKAnnotationView) {
    let calloutView = ...
    calloutView.translatesAutoresizingMaskIntoConstraints = false
    calloutView.backgroundColor = UIColor.lightGrayColor()
    view.addSubview(calloutView)

    NSLayoutConstraint.activateConstraints([
        calloutView.bottomAnchor.constraintEqualToAnchor(view.topAnchor, constant: 0),
        calloutView.widthAnchor.constraintEqualToConstant(60),
        calloutView.heightAnchor.constraintEqualToConstant(30),
        calloutView.centerXAnchor.constraintEqualToAnchor(view.centerXAnchor, constant: view.calloutOffset.x)
    ])
}

@interface CustomeAnnotationView : MKAnnotationView
@property (strong, nonatomic) UIButton *buttonCustomeCallOut;
- (void)setSelected:(BOOL)selected animated:(BOOL)animated;
@end

@implementation CustomeAnnotationView

-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}


- (void)setSelected:(BOOL)selected animated:(BOOL)animated{

    [super setSelected:selected animated:animated];

    if(selected)
    {



            self.buttonCustomeCallOut = [UIButton buttonWithType:UIButtonTypeCustom];//iconShare//iconShareBlue

            [self.buttonCustomeCallOut addTarget:self action:@selector(buttonHandlerCallOut:) forControlEvents:UIControlEventTouchDown];
        [self.buttonCustomeCallOut setBackgroundColor:[UIColor blueColor]];

            [self.buttonCustomeCallOut setFrame:CGRectMake(-40,-80, 100, 100)];



            [self addSubview:self.buttonCustomeCallOut];

        [self.buttonCustomeCallOut setUserInteractionEnabled:YES];
    }
    else
    {
        //Remove your custom view...
        [self.buttonCustomeCallOut setUserInteractionEnabled:NO];
        [self.buttonCustomeCallOut removeFromSuperview];

        self.buttonCustomeCallOut=nil;
    }
}
-(void)buttonHandlerCallOut:(UIButton*)sender{
    NSLog(@"Annotation Clicked");
}

- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent*)event
{
    UIView* v = [super hitTest:point withEvent:event];
    if (v != nil)
    {
        [self.superview bringSubviewToFront:self];
    }
    return v;
}

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event
{
    CGRect rec = self.bounds;
    BOOL isIn = CGRectContainsPoint(rec, point);
    if(!isIn)
    {
        for (UIView *v in self.subviews)
        {
            isIn = CGRectContainsPoint(v.frame, point);
            if(isIn)
                break;
        }
    }
    return isIn;
}
@end

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
    static NSString *identifier = @"CustAnnotation";

        CustomeAnnotationView *annotationView = (CustomeAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
        if (annotationView == nil) {
            annotationView = [[CustomeAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
        }

        annotationView.enabled = YES;
        annotationView.canShowCallout = NO;
        annotationView.centerOffset = CGPointMake(0,-10);//-18

        return annotationView;
}