title: Reset appearance settings for UINavigationBar back to default
body: <p>I've been using the fantastic <code>[[UINavigationBar appearance] set...</code> to set application wide appearances for my UI. However, I'm using the <code>SKStoreProductViewController</code> and want to remove all of my styling so that it shows the default Apple UI. Weirdly, without doing anything, I get a mish mash of normal UI and my custom UI, which I don't really understand. I've tried countering all my UI changes like this:</p>
  
  <pre><code>    [storeController.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
      [storeController.navigationController.navigationBar setTitleTextAttributes: [NSDictionary dictionaryWithObjectsAndKeys:
                                                             nil, UITextAttributeTextColor,
                                                             nil, UITextAttributeTextShadowColor,
                                                             nil]];
  
      [storeController.navigationController.navigationBar setTitleVerticalPositionAdjustment:0 forBarMetrics:UIBarMetricsDefault];
      [storeController.navigationController.navigationItem.leftBarButtonItem setBackgroundVerticalPositionAdjustment:0 forBarMetrics:UIBarMetricsDefault];
  </code></pre>
  
  <p>But that doesn't seem to work, making no difference at all. How can I set it back to the default UI settings?</p>
  
  <p>Regards, <br>
  Mike</p>