DocumentInteractionController Navigation Bar Color - ios

Question

In my iOS application, I am using the DocumentInteractionController to preview the .csv document.
self.documentController = [UIDocumentInteractionController interactionControllerWithURL:fileLocation];
[self.documentController setDelegate:self];
[self.documentController presentPreviewAnimated:YES];
However, I am finding that the navigation bar is completely transparent. The back button is white, so it is not visible due to the white background.
Note that I have styled the navigation bar in the AppDelegate:
[[UINavigationBar appearance] setBarTintColor:[UIColor colorWithRed:0/255.0f green:138/255.0f blue:188/255.0f alpha:1.0f]];
[[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];
[[UINavigationBar appearance] setTitleTextAttributes:#{NSFontAttributeName:[UIFont fontWithName:#"DINPro-Bold" size:17]}];
[[UINavigationBar appearance] setBackgroundImage:[[UIImage alloc] init] forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
[[UINavigationBar appearance] setShadowImage:[UIImage imageNamed:#"shadow"]];
[[UITabBar appearance] setSelectedImageTintColor:[UIColor whiteColor]];
[[UITabBar appearance] setTintColor:[UIColor whiteColor]];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent animated:NO];
Essentially, my question is how can I make the appearance of the navigation bar in the DocumentInteractionController View Controller consistent with the appearance of the navigation bar throughout the entire app (or at least visible!).

Answer 1

This line puts a transparent (or rather void) background image to your UINavigationBar. Why is that?
[[UINavigationBar appearance] setBackgroundImage:[[UIImage alloc] init] forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
Just remove the line and everything works well.
If you want to set a shadow image, then you should think about using appearanceWhenContainedIn: instead of appearance so it won't spread to unhandled controllers.
As for the Status Bar Style, the simplest way would be to pass self.navigationController as the presenter, instead of self:
- (UIViewController *) documentInteractionControllerViewControllerForPreview: (UIDocumentInteractionController *) controller {
return self.navigationController;
}
Hope this will help,