在 AppDelegate 中设置 barButtonItem

Question

如何在 AppDelegate 中设置 barButtonItem？现在我有了这个代码：

func presentDetailViewController(_ hallID: String) {

    let storyboard = UIStoryboard(name: "Main", bundle: nil)

    let navVC = UINavigationController()

    let newDetailVC = storyboard.instantiateViewController(withIdentifier: "newDetailVC") as! NewDetailTableViewController

    newDetailVC.hallID = hallID

    navVC.viewControllers = [newDetailVC]

    let backItem = UIBarButtonItem(title: "Back", style: .plain, target: self, action: #selector(AppDelegate.goToMainVC))
    navVC.navigationItem.setRightBarButton(backItem, animated: true)

    window?.rootViewController = navVC 

    window?.makeKeyAndVisible()

}

@objc func goToMainVC() {

    let storyboard = UIStoryboard(name: "Main", bundle: nil)

    let navVC = UINavigationController()

    let mainVC = storyboard.instantiateViewController(withIdentifier: "MainVC") as! PhotoStudiosViewController

    navVC.viewControllers = [mainVC]

    window?.rootViewController = navVC

    window?.makeKeyAndVisible()

}

let backItem = UIBarButtonItem(title: "Назад", style: .plain, target: self, action: #selector(AppDelegate.goToMainVC)) navVC.navigationItem.setRightBarButton(backItem, animated: true)

这条线对我没有帮助，barButtonItem 仍然没有出现。如何用我的操作 func goToMainVC 创建 backButton？

Answer 1

您没有将导航项设置为导航控制器，而是将导航项设置为 viewController

的导航栏

所以将您的代码更改为

let newDetailVC = storyboard.instantiateViewController(withIdentifier: "newDetailVC") as! NewDetailTableViewController
let backItem = UIBarButtonItem(title: "Back", style: .plain, target: self, action: #selector(AppDelegate.goToMainVC))
//navVC.navigationItem.setRightBarButton(backItem, animated: true) this is the issue
newDetailVC.navigationItem.setRightBarButton(backItem, animated: true)

希望对您有所帮助

在 AppDelegate 中设置 barButtonItem

Set barButtonItem in AppDelegate

ios

swift

xcode

uibarbuttonitem

appdelegate