Black bar between navigation bar and table view appears on iOS 6 - objective-c

Question

I seem to be having an issue since I started using iOS 6, which doesn't appear when using iOS 5. At first, I thought it might just be a simulator bug, but since testing it on my iPhone 5 today, I can see that it's not just in the simulator.
I'm creating everything programmatically — I seem to prefer doing it that way (I assume it's because of my HTML/CSS background!) — but I'm still reasonably new to Objective-C, and I couldn't find a full example of how to set up a navigation controller/table view programmatically, so I put it together from the nuggets of information I could find, and therefore, I could be doing something fundamentally wrong. However, it's worked (and still works) perfectly on iOS 5.
The problem is that I have a black bar between the navigation bar and the table view, but the strange thing is that if I push a view and go back to that original view, the bar disappears, and doesn't reappear until I completely restart the app.
The following image is of the app at launch (1), as I'm pushing a view in (2), and the initial view, after I've gone back to it (3):
This is what I have as my code:
AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
RootViewController *rootController = [[RootViewController alloc] init];
self.window.rootViewController = rootController;
self.navigationController = [[UINavigationController alloc] initWithRootViewController:rootController];
[self.window addSubview:navigationController.view];
[self.window makeKeyAndVisible];
NSLog(#"Window frame: %#", NSStringFromCGRect(self.window.frame));
return YES;
}
RootViewController.m
- (void)loadView
{
self.title = #"Title";
self.tableView = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen] bounds] style:UITableViewStylePlain];
self.tableView.delegate = self;
self.tableView.dataSource = self;
self.view = self.tableView;
NSLog(#"tableView frame: %#", NSStringFromCGRect(self.tableView.frame));
UIBarButtonItem *newViewButton = [[UIBarButtonItem alloc] initWithTitle:#"New View"
style:UIBarButtonItemStylePlain
target:self
action:#selector(newViewButtonTapped:)];
[self.navigationItem setRightBarButtonItem:newViewButton animated:NO];
}
I added the NSLogs to see if they showed anything that might help me. The output is:
tableView frame: {{0, 0}, {320, 480}}
Window frame: {{0, 0}, {320, 480}}
Can anyone give me any ideas about what I'm doing wrong? It seems is having a similar/the same problem (Black bar overtop navigation bar — in the comments), but I haven't found an answer.
Thanks, in advance!

Answer 1

You're adding the RootViewController to the window twice, once by setting UIWindow.rootViewController (which internally does [window addSubview:rootViewController.view]) and again by adding it as a subview of the navigation controller.
You should be doing this:
RootViewController *rootController = [[RootViewController alloc] init];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:rootController];
self.window.rootViewController = navigationController;
As a rule of thumb, never add a view directly to the window unless you know that you actually want to.