title: Unable to make Navigation Bar totally transparent in iOS6
body: <p>I was using the following code to make my Navigation Bar transparent in iOS5:</p>
  
  <pre><code>const float colorMask[6] = {222, 255, 222, 255, 222, 255};
  UIImage *img = [[UIImage alloc] init];
  UIImage *maskedImage = [UIImage imageWithCGImage: CGImageCreateWithMaskingColors(img.CGImage, colorMask)];
  [self.navigationController.navigationBar setBackgroundImage:maskedImage forBarMetrics:UIBarMetricsDefault];
  </code></pre>
  
  <p>Upgraded to iOS6 and the Navigation Bar is still transparent but now has a thin black line underneath it.  How can I make the Navigation Bar totally transparent?</p>
  
  <p>I have also tried all of the following:</p>
  
  <pre><code>self.navigationController.navigationBar.translucent = YES;
  self.navigationController.navigationBar.opaque = YES;
  self.navigationController.navigationBar.tintColor = [UIColor clearColor];
  self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];
  [self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
  [self.navigationController.navigationBar setBarStyle:UIBarStyleBlackTranslucent];
  [[UINavigationBar appearance] setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
  </code></pre>
  
  <p>Thanks in advance.</p>