如何在iOS中导航屏幕时始终显示视图控制器？

// 在AppDelegate中创建导航控制器
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    let rootViewController = YourRootViewController() // 替换为你的根视图控制器
    let navigationController = UINavigationController(rootViewController: rootViewController)
    
    // 设置导航栏样式等其他配置
    
    window?.rootViewController = navigationController
    window?.makeKeyAndVisible()
    
    return true
}

// 在需要显示视图控制器的地方，使用以下代码进行导航
func navigateToTargetViewController() {
    let targetViewController = YourTargetViewController() // 替换为你的目标视图控制器
    navigationController?.pushViewController(targetViewController, animated: true)
}

// 在需要返回到目标视图控制器的地方，使用以下代码进行导航
func navigateBackToTargetViewController() {
    if let viewControllers = navigationController?.viewControllers {
        for viewController in viewControllers {
            if viewController is YourTargetViewController { // 替换为你的目标视图控制器
                navigationController?.popToViewController(viewController, animated: true)
                break
            }
        }
    }
}