ios – 状态栏大小错误,包含UINavigationController

我通过包含使UINavigationController成为另一个视图控制器的子节点.一切正常,除了在打开呼叫状态栏打开时启动应用程序时出现的奇怪问题,然后在应用程序UI在屏幕上后将其切换回OFF.在状态栏的位置出现了一个奇怪的黑色间隙.

考虑下面的自包含示例应用程序：

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong,nonatomic) UIWindow *window;
@end

@implementation AppDelegate
- (BOOL)application:(UIApplication *)app didFinishLaunchingWithOptions:(NSDictionary *)opt
{
  // Content
  UILabel * aLbl = [[UILabel alloc] initWithFrame:CGRectMake(20,100,200,40)];
  aLbl.text = @"In-call status bar issue";

  UIViewController * aContent = [[UIViewController alloc] init];
  aContent.title = @"Title";
  aContent.view.backgroundColor = UIColor.whiteColor;
  [aContent.view addSubview:aLbl];

  UINavigationController * aNav = [[UINavigationController alloc]
    initWithRootViewController:aContent];

  // Parentmost view controller containing the navigation view controller
  UIViewController * aParent = [[UIViewController alloc] init];
  [aParent.view addSubview:aNav.view];
  [aParent addChildViewController:aNav];
  [aNav didMovetoParentViewController:aParent];

  self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds];
  self.window.rootViewController = aParent;
  [self.window makeKeyAndVisible];

  return YES;
}
@end

int main(int argc,char ** argv)
  { @autoreleasepool { return UIApplicationMain(argc,argv,nil,@"AppDelegate"); } }

重现问题的最简单方法是：

>启动iOS模拟器.
>按⌘Y打开通话中状态栏.状态栏将变为宽绿色.
>手动启动应用程序并等待导航控制器出现.
>再次按⌘Y可关闭通话中状态栏.

UI现在应该如下所示：

有谁知道如何解决这个问题？

aNav.view.frame = aParent.view.bounds;
aNav.view.autoresizingMask = 
    UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;