iOS7下隱藏status bar的詳細研究

info.plist文件中，View controller-based status bar appearance項設爲YES，則View controller對status bar的設置優先級高於application的設置。爲NO則以application的設置爲準，view controller的prefersStatusBarHidden方法無效，是根本不會被調用的。

 

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

這時 view controller中對status bar的設置優先級高於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)prefersStatusBarHidden
2 {
3     return YES;
4 }

 

2．View controller-based status bar appearance設爲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

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

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

 

• 若是View controller-based status bar appearance 設爲YES，則須要判斷當前是iOS6仍是iOS7。

　　若是是iOS6，則還經過sharedApplication隱藏。

　　若是是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 }