I have subclassed the MKAnnotatonView and overrode the initWithAnnotation:resueIdentifier and drawRect methods to add another image behind the "front" image.
It seems that that is what Apple's MKAnnotationView class reference is suggesting us to do.
Only that it is tricky. If you are subclassing the MKAnnotationView, there is still the image property existing. They have done something about the properly so that it is linked with drawing. Perhaps, they have overridden the drawRect to draw the image AFTER the initialization is done.
Also, if you don't set the image property, the frame of your custom annotationView is set to size 0, and the drawRect method does not get called.
Finally, Apple says that the images should be totally filled, i.e. uses a transparent colour for the background of the drawings.
So: In your subclass:
- (id)initWithAnnotation:(id <MKAnnotation>)annotation reuseIdentifier:(NSString *)identifier
{
self = [super initWithAnnotation:annotation reuseIdentifier:identifier];
if (self)
{
UIButton *rightButton = [UIButton buttonWithType: UIButtonTypeDetailDisclosure];
[rightButton addTarget:self
action:@selector(myShowAnnotationAddress:)
forControlEvents:UIControlEventTouchUpInside];
self.rightCalloutAccessoryView = rightButton;
self.canShowCallout = YES;
self.multipleTouchEnabled = NO;
self.frame = CGRectMake(0, 0, 65, 100);
self.backgroundColor = [UIColor clearColor];
return self;
}
return nil;
}
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGPoint drawPoint = CGPointMake(0.0f, 0.0f);
UIImage *shadowImage = [UIImage imageNamed:@"shadow_image.png"];
[shadowImage drawAtPoint:drawPoint];
UIImage *frontImage = [UIImage imageNamed:@"front_image.png"];
[frontImage drawAtPoint:drawPoint];
CGContextRestoreGState(context);
}
After I made the answer, I realize that you actually wanted to draw behind MKPinAnnotationView. My answer is not that, although it shows where the drawing perhaps should be done. Obviously MKPinAnnottions has its own drawing method to present a Pin and its shadow.
I think that probably you can retrieve the Pin image from the self.image property. As to the shadow, I am not certain... It may be using OPEN GL drawing method to add the shadow, or simply combining a shadow image.
Finally, the image comes with animation. I am guessing that that is where the animation is run. At this stage, though, I have not tested.
