draw circle on MKMapview in iphone app

I am trying to draw circles around the current location on MKMapview.I tryied many codes but however no success. can any one suggest any links which should I refer. I am new to Iphone so dont have much knowledge abou开发者_高级运维t Quartz 2D.

I would think the simplest method to achieve your goal would be to use a custom PNG image with transparency and set the image property of a MKAnnotationView that you add to your current MKMapView.