title: QLPreviewController NavigationBar setTranslucent property not working
body: <p>i have set the custom color to navigation bar of QLPreviewController
  but the problem is that i want dark color of navigation bar in QLPreviewController
  even i have set the navigation bar translucent property to No
  But i Dont know Why it is not working</p>
  
  <p>I want it like belowed image</p>
  
  <p><img src="https://i.stack.imgur.com/MRYx0.png" alt="enter image description here"></p>
  
  <p>but it shows like  this image</p>
  
  <p><img src="https://i.stack.imgur.com/8PiLs.png" alt="enter image description here"></p>
  
  <pre><code>QLPreviewController *previewer = [[QLPreviewController alloc] init];
  // Set data source
  [previewer setDataSource:self];
  [previewer setDelegate:self];
  // Which item to preview
  [previewer setCurrentPreviewItemIndex:index];
  [previewer.view addGestureRecognizer:singleTap];
  previewer.navigationController.navigationBar.translucent = NO;
  previewer.navigationController.navigationBar.barTintColor = [UIColor redColor];
  self.navigationController.navigationBar.translucent=NO;
  self.navigationController.navigationBar.barTintColor = [UIColor redColor];
     [self.navigationController pushViewController:previewer animated:TRUE ];
  </code></pre>
  
  <p>even i have also tried like this but it is also not working</p>
  
  <pre><code>    - (id &lt;QLPreviewItem&gt;)previewController: (QLPreviewController *)controller previewItemAtIndex:(NSInteger)index
  {
  // Break the path into it's components (filename and extension)
  // Use the filename (index 0) and the extension (index 1) to get path
  //lblFileName.text=[strFileName stringByReplacingOccurrencesOfString:@"movefile" withString:@""];
  
  // For navigation bar color and text attributes of navigation bar
  for (id object in controller.childViewControllers)
  {
      if ([object isKindOfClass:[UINavigationController class]])
      {
          UINavigationController *navController = object;
          navController.navigationBar.translucent=NO;
          navController.navigationBar.barTintColor = [UIColor redColor];;
          navController.toolbar.translucent=NO;
          navController.toolbar.barTintColor=[UIColor redColor];;
          [navController.navigationBar setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIColor whiteColor], NSForegroundColorAttributeName, nil]];
  
  
      }
  }
  
     NSString *strFilename=[[NSBundle mainBundle]pathForResource:@"final" ofType:@"png"];
  
  return [NSURL fileURLWithPath:strFilename];
  }
  </code></pre>
  
  <p>Please suggest me where i am going wrong
  Thanks In Advance</p>