ios - 从 AppDelegate 内部执行 pushViewController

Question

在我的 iOS 应用程序中，我想在推送通知事件到达时打开一个新的 View Controller 。我尝试在 AppDelegate.swift 内部跟随来处理导航。

let friendStoryboard = UIStoryboard(name: "Profile", bundle: nil)
let friendsVC = friendStoryboard.instantiateViewController(withIdentifier: "FriendsViewIdentifier") as! FriendsViewController
let backItem = UIBarButtonItem()
backItem.title = ""
self.window?.rootViewController?.navigationItem.backBarButtonItem = backItem
self.window?.rootViewController?.navigationController?.pushViewController(friendsVC, animated: true)

但它仍然无法处理 View Controller 的导航。我怎样才能使它工作？

所以在这种情况下，我的 View Controller 层次结构不包含 UiNavigationController。层次结构如下。

Answer 1

Else block 会给你一个答案。

if let friendStoryboard: UIStoryboard = UIStoryboard(name: "Profile", bundle: nil) {
        if let friendsVC = friendStoryboard.instantiateViewController(withIdentifier: "FriendsViewIdentifier") as? FriendsViewController {

            let backItem = UIBarButtonItem()
            backItem.title = ""
            self.window?.rootViewController?.navigationItem.backBarButtonItem = backItem

            if let navController = self.window?.rootViewController as? UINavigationController {
                navController.pushViewController(friendsVC, animated: true)
            } else if let tabController = self.window?.rootViewController as? UITabBarController {

                if let tabViewControllers = tabController.viewControllers {

                    if let navController = tabViewControllers.first as? UINavigationController {
                        navController.pushViewController(friendsVC, animated: true)

                    } else {
                        print("tabViewControllers.first as? UINavigationController not found")
                    }

                }  else {
                    print("tabViewControllers count is zero")
                }

            } else {
                print("UINavigationController & UITabBarController not found at self.window?.rootViewController")
            }

        } else {
            print("FriendsViewController not found")
        }

    } else {
        print("friendStoryboard not found")
}