在呈现新的UITabBarController之前如何关闭rootViewController? [英] How do I dismiss a rootViewController before presenting a new UITabBarController?

问题描述

我已经在AppDelegate中将UIViewController设置为rootViewController，但是，当用户登录或跳过UIViewController时，我会在顶部显示一个UITabBarController.

I've set up a UIViewController as my rootViewController in AppDelegate, however, when a user logs in or skips it I am presenting a UITabBarController over the top.

我需要关闭LoginController，然后在用户登录后将UITabController设置为rootViewController.

I need to dismiss the LoginController, and set the UITabController as rootViewController instead after user logs in.

我该如何进行重组?

AppDelegate()

AppDelegate()

window = UIWindow()
window?.makeKeyAndVisible()
window?.rootViewController = LoginController()

LoginController()

LoginController()

self.present(MainTabBarController(), animated: true, completion: nil)

推荐答案

维护状态对于用户是否登录(然后根据该状态)很容易.您可以导航到视图.

It's too easy to maintain condition for user logged in or not, and then based on that status. You can navigate to your view.

您可以尝试这种方式:

1.在 AppDelegate 中，您可以使用这些方法.

1.In AppDelegate you can these methods.

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

    let isLogin = UserDefaults.standard.bool(forKey: "IS_LOGIN")
    if isLogin == true {
        self.goToDashboardView()
    } else {
        self.goToLoginView()
    }
    return true
}

//MARK:- ------- Global Methods -------

class func sharedInstance() -> AppDelegate {
    return UIApplication.shared.delegate as! AppDelegate
}

func goToLoginView() {

    let sb = UIStoryboard.init(name: "Main", bundle: nil)
    let loginVC = sb.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
    let navVC = UINavigationController(rootViewController: loginVC) // You can skip this if you do not want to add navigation bar
    self.window?.rootViewController = navVC // if you skipped above line, then you have to assign 'loginVC' here.
    self.window?.makeKeyAndVisible()
}

func goToDashboardView() {

    let sb = UIStoryboard.init(name: "Main", bundle: nil)
    let tabbarVC = sb.instantiateViewController(withIdentifier: "MyTabBarController") as! MyTabBarController
    self).window?.rootViewController = tabbarVC // if you skipped above line, then you have to assign 'loginVC' here.
    self.window?.makeKeyAndVisible()
}

2.用户成功登录后，在 LoginViewController 中.

2.In LoginViewController, when user logged in successfully.

@IBAction func btnLoginClicked(_ sender: UIButton) {

    // Your API call or other code
    // If all things goes well, then login and go to dashboard

    UserDefaults.standard.set(true, forKey: "IS_LOGIN")
    AppDelegate.sharedInstance().goToDashboardView()
}

3.最后，只要您想从应用程序中注销，无论何时何地，只需调用以下代码即可.

3.And finally, whenever and from wherever you want to log out from app, just call below code.

@IBAction func btnLogOutClicked(_ sender: UIButton) {

    // Your API call or other code
    // If all things goes well, then logout and go to login view

    UserDefaults.standard.set(false, forKey: "IS_LOGIN")
    AppDelegate.sharedInstance().goToLoginView()
}

4. Main.storyboard 的设计应类似于:

4.And Main.storyboard should have design something like :

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