### `UIStatusBarStyle` in iOS 7

* The status bar in iOS 7 is transparent, the view behind it shows through.

* The style of the status bar refers to the appearances of its content. In iOS 7, the status bar content is either dark (`UIStatusBarStyleDefault`) or light (`UIStatusBarStyleLightContent`). Both `UIStatusBarStyleBlackTranslucent` and `UIStatusBarStyleBlackOpaque` are deprecated in iOS 7.0. Use `UIStatusBarStyleLightContent` instead.

### How to change `UIStatusBarStyle`

* If below the status bar is a navigation bar, the status bar style will be adjusted to match the navigation bar style (`UINavigationBar.barStyle`):

  Specifically, if the navigation bar style is `UIBarStyleDefault`, the status bar style will be `UIStatusBarStyleDefault`; if the navigation bar style is `UIBarStyleBlack`, the status bar style will be `UIStatusBarStyleLightContent`.

* If there is no navigation bar below the status bar, the status bar style can be controlled and changed by an individual view controller while the apps.

  `-[UIViewController preferredStatusBarStyle]` is a new method added in iOS 7. It can be overridden to return one type of status bar style:
  
		- (UIStatusBarStyle)preferredStatusBarStyle
		{
			return UIStatusBarStyleLightContent;
		}
  		
* If the status bar style should be controlled by a child view controller instead of `self`, override `-[UIViewController childViewControllerForStatusBarStyle]` to return that child view controller.

* If you prefer to opt out of this behavior and set the status bar style by using the `-[UIApplication statusBarStyle]` method, add the `UIViewControllerBasedStatusBarAppearance` key to an app’s Info.plist file and give it the value `NO`.