preferredStatusBarStyle isn't called

I followed this thread to override -preferredStatusBarStyle, but it isn't called. Are there any options that I can change to enable it? (I'm using XIBs in my project.)

Possible root cause

I had the same problem, and figured out it was happening because I wasn't setting the root view controller in my application window.

The UIViewController in which I had implemented the preferredStatusBarStyle was used in a UITabBarController, which controlled the appearance of the views on the screen.

When I set the root view controller to point to this UITabBarController, the status bar changes started to work correctly, as expected (and the preferredStatusBarStyle method was getting called).

(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    ... // other view controller loading/setup code

    self.window.rootViewController = rootTabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

Alternative method (Deprecated in iOS 9)

Alternatively, you can call one of the following methods, as appropriate, in each of your view controllers, depending on its background color, instead of having to use setNeedsStatusBarAppearanceUpdate:

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

or

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];

Note that you'll also need to set UIViewControllerBasedStatusBarAppearance to NO in the plist file if you use this method.