swift - NavigationController 看不到右栏按钮项

Question

我试图通过允许用户添加算命应用程序的新结果来理解演示 View Controller 。当用户点击导航栏右上角的“添加新结果”时，会弹出一个新的 View Controller ，用户可以在此处输入新结果。我试图在演示 Controller 的右上角添加一个完成按钮，但我收到一条错误消息，提示 Value of type 'UINavigationController?'没有成员“rightBarButtonItem”。

我认为这是因为引用 topViewController 是问题所在，但我在 1 个 ViewController 中完成了这一切。

@IBAction func actionButtonTapped(_ sender: UIBarButtonItem) {
    let storyboard : UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

    let viewController = storyboard.instantiateViewController(withIdentifier: "AddNewOptionController")
    viewController.modalPresentationStyle = .popover
    let popover : UIPopoverPresentationController = viewController.popoverPresentationController!
    popover.barButtonItem = sender
    popover.delegate = self
    present(viewController, animated: true, completion: nil)
}

func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
    return .fullScreen
}

func presentationController(_ controller: UIPresentationController, viewControllerForAdaptivePresentationStyle style: UIModalPresentationStyle) -> UIViewController? {
    let navigationController = UINavigationController(rootViewController: controller.presentedViewController)
    let doneButton = UIBarButtonItem(title: "Done", style: .done, target: self, action: #selector(ViewController.dismissViewController))
//error below
     navigationController.topViewController?.navigationController.rightBarButtonItem = doneButton
    return navigationController
}

func dismissViewController() {
    self.dismiss(animated: true, completion: nil)
}

Answer 1

代替:

navigationController.topViewController?.navigationController.rightBarButtonItem = doneButton

尝试:

navigationController.topViewController?.navigationItem.rightBarButtonItem = doneButton