UINavigationController's view and 20 points offset

Question

This is an already posted question but I need to understand what is going on with the following scenario. I'm developing an iPad application and I created a UINavigationController like the following (test purposes).

UINavigationController* navigationController = [[UINavigationController alloc] init];        
navigationController.view.backgroundColor = [UIColor redColor];

Once created, I added the UINavigationController's view as a subview of a UIViewController.

[self.view addSubview:navigationController.view];

The result is displayed in the following image:

As you can see, there is a gap between the status bar and the navigation bar of the UINavigationController. Since the view of the UINavigationController is red, it seems that the frame of the navigation bar has that gap.

I've found an hack to fix the problem. By setting the frame for the UINavigationController, the navigation bar goes in the right position.

CGRect statusBarFrame = [[UIApplication sharedApplication] statusBarFrame];
CGRect frameRect = CGRectMake(navigationController.view.frame.origin.x, navigationController.view.frame.origin.y - statusBarFrame.size.height, navigationController.view.frame.size.width, navigationController.view.frame.size.height);

navigationController.view.frame = frameRect;

Now, since I don't like very much that hack and I would understand what is going on, do you have any suggestions to find an elegant solution to resolve the problem?

Thank you in advance.

Answer 1

That 20px offset is for status bar, navigation controller is designed to be full-screen, but you are adding it to the subview of the main view.

Answer 2

viewController setWantsFullScreenLayout:YES

It may help you.