Swift导航栏显示异常：安全区域与导航栏存在间隙的解决求助

我不清楚为何导航栏显示异常，从截图可见安全区域与导航栏之间存在间隙。以下是我的自定义TabBar代码：

class TabBarController: UITabBarController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.setupBar()

    }
    
    // MARK: - Tab Setup
    
    private func setupBar() {
        self.setViewControllers([travelListNC(), mapNC()], animated: true)
    }
    
    private func travelListNC() -> UINavigationController {
        let storyboard = UIStoryboard(name: "TravelListViewController", bundle: Bundle.main)
        let travelsVC = storyboard.instantiateViewController(withIdentifier: "TravelListViewController") as! TravelListViewController
        travelsVC.tabBarItem.title = "Travels"
        travelsVC.tabBarItem.image = UIImage(systemName: "list.dash")
        return UINavigationController(rootViewController: travelsVC)
    }
    
    private func mapNC() -> UINavigationController {
        let storyboard = UIStoryboard(name: "MapViewController", bundle: Bundle.main)
        let mapVC = storyboard.instantiateViewController(withIdentifier: "MapViewController") as! MapViewController
        mapVC.title = "Map"
        mapVC.tabBarItem.title = "Map"
        mapVC.tabBarItem.image = UIImage(systemName: "map.fill")
        return UINavigationController(rootViewController: mapVC)
    }

}

调用该TabBar的代码如下：

func homeView() {
        let tabBarController = TabBarController()
        let navController = UINavigationController(rootViewController: tabBarController)
        navController.modalPresentationStyle = .fullScreen
        present(navController, animated: true, completion: {
            let navController = tabBarController.viewControllers![0] as! UINavigationController
            let vc = navController.topViewController as! TravelListViewController
            vc.userLoged = self.userLoged
        })
    }

我已在TravelListViewController中设置了导航栏标题。

1. 移除多余的外层NavigationController #

你的代码将TabBarController嵌套进了另一个UINavigationController，这会造成导航栏层级混乱，是间隙出现的核心原因。直接展示TabBarController即可：

修改homeView()代码：

func homeView() {
    let tabBarController = TabBarController()
    tabBarController.modalPresentationStyle = .fullScreen
    present(tabBarController, animated: true, completion: {
        let navController = tabBarController.viewControllers![0] as! UINavigationController
        let vc = navController.topViewController as! TravelListViewController
        vc.userLoged = self.userLoged
    })
}

2. 确保安全区域适配正确 #

如果修改层级后仍有问题，检查以下设置：

• 在TravelListViewController和MapViewController中，设置正确的边缘延伸属性：

override func viewDidLoad() {
    super.viewDidLoad()
    // 让视图延伸到导航栏下方，自动适配安全区域
    self.edgesForExtendedLayout = .all
}

• 按需调整导航栏半透明属性（默认是true）：

navigationController?.navigationBar.isTranslucent = false

3. 检查Storyboard布局约束 #

打开对应Storyboard文件，确保ViewController根视图的顶部约束连接到安全区域顶部，而非视图顶部，避免出现间隙。

内容的提问来源于stack exchange，提问作者Boguhe Stephane