Rounded corners of MKMapView

Answer 1

Take a look at the last paragraph of the Overview section in the MKMapView class reference:

Although you should not subclass the MKMapView class itself,...

I think that pretty well answers your question of whether you should subclass it. One thing you could do is put another view on top of the MKMapView that looks like the background to round the corners. If you need it to be of arbitrary size, you can try the strechableImage method on UIImage.

Answer 2

The easiest way to make round corner:

#import <QuarzCore.framework/QuarzCore.h>
myMapView.layer.cornerRadius = 10.0;

Answer 3

Just a small correction as the import statement is misspelt in digdog's answer.

Should be

#import <QuartzCore/QuartzCore.h>
myMapView.layer.cornerRadius = 10.0;