title: UIButton as UINavigationbar button
body: <p>I have a Tab bar application. and in one of the tab bars I have a navigation contorller.
  Im trying to set a UIButton with an image as the right button the navigation bar.</p>
  
  <pre><code>    UIButton *refreshButton = [[UIButton alloc] init];
      [refreshButton setImage:[UIImage imageNamed:@"refresh_icon.png"] forState:UIControlStateNormal];
      [refreshButton addTarget:self action:@selector(refreshSection) forControlEvents:UIControlEventTouchUpInside];
      UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithCustomView:refreshButton];
      //[rightButton setImage:[UIImage imageNamed:@"refresh_icon.png"]]; &lt;&lt; DOESN'T WORK EITHER  
      self.navigationItem.rightBarButtonItem = rightButton;
      [refreshButton release];
      [rightButton release];
  </code></pre>
  
  <p>but the image doesn't show up. I get an invisible button. </p>
  
  <p><strong>EDIT:</strong>
  I want the button style to be plain or background to be transparent, so that only the image shows. Hence I am using a UIbutton instead of using a UIBarButton directly.</p>