title: iOS 8: UINavigationController hide back button
body: <p>After I run my application in iOS 8 (XCode 6.0.1, iPhone 6), the back button does not hide.</p>
  
  <p>My code:</p>
  
  <pre><code>- (void)removeCategoriesButton
  {
      if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
          [_navigationController.topViewController.navigationItem setHidesBackButton:YES];
          [_navigationController.topViewController.navigationItem setLeftBarButtonItem:nil];
      } else {
          UIViewController *controller = _app.window.rootViewController;
  
          if ([controller isKindOfClass:[UINavigationController class]]) {
              UINavigationController *nav = (UINavigationController *)controller;
              [nav.topViewController.navigationItem setHidesBackButton:YES];
              [nav.topViewController.navigationItem setLeftBarButtonItem:nil];
          }
      }
  }
  </code></pre>
  
  <p>But the back button does not hide (see screenshot):</p>
  
  <p><img src="https://i.stack.imgur.com/RkQv5.png" alt="Simulator screen"></p>
  
  <p><strong>UPD:</strong></p>
  
  <p>I run application in another simulators, and i see this "bug" only on iOS 8.</p>