info.plist文件中，View controller-based status bar appearance項設為YES，則View controller對status bar的設置優先級高于application的設置。為NO則以application的設置為準，view controller的PRefersstatusBarHidden方法無效，是根本不會被調用的。

1．View controller-based status bar appearance設為YES。

這時 view controller中對status bar的設置優先級高于application的設置，用下面的方式隱藏status bar。

1.1 在view controller中調用setNeedsStatusBarAppearanceUpdate，更新status bar的顯示

 1 - (void)viewDidAppear:(BOOL)animated 2 { 3     [super viewDidAppear:animated]; 4  5     if ([self respondsToSelector:@selector(setNeedsStatusBarAppearanceUpdate)]) { 6         [self prefersStatusBarHidden]; 7         [self performSelector:@selector(setNeedsStatusBarAppearanceUpdate)]; 8     } 9 }    

1.2 覆蓋view controller的prefersStatusBarHidden的實現，返會YES。

1 - (BOOL)prefersStatusBarHidden2 {3     return YES;4 }

2．View controller-based status bar appearance設為NO

這時application的設置優先級最高，用下面的方式隱藏status bar:

1 [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:NO];

3．結論

• 如果View controller-based status bar appearance 設為NO，iOS6和iOS7都是用下面的方法隱藏status bar。

1 [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:NO];

• 如果View controller-based status bar appearance 設為YES，則需要判斷當前是iOS6還是iOS7。

　　如果是iOS6，則還通過sharedApplication隱藏。

　　如果是iOS7，則用setNeedsStatusBarAppearanceUpdate加prefersStatusBarHidden的方式來隱藏 status bar。

4．取info.plist中 View controller-based status bar appearance中的設置

 1 NSNumber *isVCBasedStatusBarAppearanceNum = [[NSBundle mainBundle]objectForInfoDictionaryKey:@"UIViewControllerBasedStatusBarAppearance"]; 2 if (isVCBasedStatusBarAppearanceNum) { 3     _isVCBasedStatusBarAppearance = isVCBasedStatusBarAppearanceNum.boolValue; 4 } else { 5     _isVCBasedStatusBarAppearance = YES; // default 6 }