title: UIButton backgroundImage stretchableImageWithLeftCapWidth:topCapHeight issue
body: <p>I have a <code>UIButton</code> with a specified width of 200. Its <code>autoresizingMask</code> property is set to <code>UIViewAutoresizingFlexibleWidth</code>. A <code>UIImage</code> is applied to this button's <code>backgroundImage</code> property. This <code>UIimage</code> is defined as follows:</p>
  
  <pre><code>[[UIImage imageNamed:@"buttonimage.png"] stretchableImageWithLeftCapWidth:10 topCapHeight:0]
  </code></pre>
  
  <p><code>buttonimage.png</code> has a width of 400px (2x width of button, because of retina resolution) and represents a rounded rectangle. In portrait mode, everything is fine. As soon as the user rotates the device and the iPhone enters landscape mode, the <code>UIButton</code> is stretched. Due to this behaviour, the left rounded border of the image stays the same (<code>stretchableImageWithLeftCapWidth:</code>) but the right corners are also stretched. Is there any property I forgot to set that ensures only one specified pixel (e.g. the tenth one) is stretched and anything else retains it dimensions?</p>
  
  <p>Thanks in advance!</p>
  
  <p>Edit: If I use a smaller image, that is already stretched in portrait mode, both borders seem to be expanded.</p>
  
  <p><strong>Solved!</strong>
  If your image is called "myImage.png" and it is the retina version, just call it "myImage@2x.png"</p>