title: Drawing concentric circle : Inner circle should be filled
body: <p>Im trying to achieve a button shapped as<img src="https://i.stack.imgur.com/ELqws.png" alt="enter image description here"></p>
  
  <p>This is the current code I'm trying . It achieves concentric circle but the outer one is filled instead. Help.</p>
  
  <pre><code> CGContextRef ctx = UIGraphicsGetCurrentContext();
      CGContextAddEllipseInRect(ctx, rect);
      CGContextAddEllipseInRect(ctx, 
                  CGRectMake(
                      rect.origin.x + 10, 
                      rect.origin.y + 10, 
                      rect.size.width - 20, 
                      rect.size.height - 20));
      CGContextSetFillColor(ctx, CGColorGetComponents([[UIColor blueColor] CGColor]));
      CGContextEOFillPath(ctx);
  </code></pre>