解決方法：
1.在plist文件中將 View controller-based status bar appearance 設(shè)置為NO
2.在application:didFinishLaunchingWithOptions:中添加下面代碼
[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationNone];
[[UIApplication sharedApplication] setStatusBarHidden:NO withAnimation:UIStatusBarAnimationNone];
