ios - tabBarController 选定的索引在 viewController 中不起作用 [Swift]

Question

在我的 iOS 应用程序中，我有一个包含 3 个项目的 tabBarController。当用户点击第二个项目时，会出现一个 View (CreateCommentsViewController)，然后当用户点击关闭按钮时，我想更改 tabBarController 的选定索引(从 1 到 0)，但它不能以这种方式工作:

class CreateCommentViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()

}

func getTabBarController() -> UITabBarController? {
    let appDelegate = UIApplication.shared.delegate as! AppDelegate

    guard let tabBarController = appDelegate.window?.rootViewController as? UITabBarController else { return nil }
    return tabBarController
}

@IBAction func dismissNewCommentView(_ sender: UIBarButtonItem) {

    let tabBarController = getTabBarController()!

    self.dismiss(animated: true) {
        tabBarController.selectedIndex = 0
    }
}
}

还有应用程序委托(delegate)代码:

class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    window = UIWindow(frame: UIScreen.main.bounds)
    window!.rootViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(identifier: VIEW_CONTROLLER_IDS.TAB_BAR_CONTROLLER) as! UITabBarController
    window!.makeKeyAndVisible()

    return true
}

Answer 1

尝试更新您的操作(如果您使用 Swift 5 & 5.1 & 5.2):

@IBAction func dismissNewCommentView(_ sender: UIBarButtonItem) {
    self.dismiss(animated: true) {
        if let tabBarController = UIApplication.shared.windows.first?.rootViewController as? UITabBarController {
            tabBarController.selectedIndex = 0
        }
    }
}