Using a UINavigationController and setting its navigation bar's barStyle to .Black. past this line in your AppDelegate.m file.
navigationController.navigationBar.barStyle = UIBarStyleBlack;
If you are not using UINavigationController then add following code in your ViewController.m file.
- (UIStatusBarStyle)preferredStatusBarStyle
{
return UIStatusBarStyleLightContent;
}
And call the method to this line :
[self setNeedsStatusBarAppearanceUpdate];