Question

我的代码是

#import "AppDelegate"

在viewDidLoad

中

self.delegate = (AppDelegate *) [[UIApplication sharedApplication] delegate];

收到回复后

//If server response is success make HomeViewController as Root VC
if ([[[_response objectForKey:@"Response"] objectForKey:@"status"]  isEqualToString:@"SUCCESS"]) {

dispatch_async(dispatch_get_main_queue(), ^{

//Make root view controller
UIStoryboard *mainStoryBoard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; //My storyboard name is Main.storyboard
HomeViewController * hvc = [mainStoryBoard instantiateViewControllerWithIdentifier:@"HVC"];
self.delegate.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:hvc];
[self.delegate.window makeKeyAndVisible];

});
}

但它不起作用......

Answer 1

SWIFT代码 在Appdelegate类中实现两个方法，如下所示： -

    class AppDelegate: UIResponder, UIApplicationDelegate {
        var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

            application.statusBarStyle = .lightContent
            self.window = UIWindow(frame: UIScreen.main.bounds)
            self.window?.makeKeyAndVisible()

            return true
        }
        func showTabBar()  {

            let tabBarContoller = UIStoryboard(name: OTPStoryBoards.Booking, bundle: nil).instantiateViewController(withIdentifier: OTPViewControllers.TabBarController) as! UITabBarController
            self.window?.rootViewController = tabBarContoller
        }

        func showLogin()  {
            let loginVC = UIStoryboard(name: OTPStoryBoards.Authentication, bundle: nil).instantiateViewController(withIdentifier: OTPViewControllers.LoginVC) as! OTPLoginViewController
            let navigationControler = UINavigationController(rootViewController: loginVC)
            self.window?.rootViewController = navigationControler
        }
}

每当你想改变root调用这些方法

let APP_DELEGATE    = UIApplication.shared.delegate as! AppDelegate

  APP_DELEGATE.showLogin() or APP_DELEGATE.showTabBar()

Answer 2

在LoginViewController中，您需要跟踪用户成功登录的用户登录状态。为此，您可以在UserDefaults中存储bool var，如...

UserDefaults.standard.setValue(true, forKey: "isUserLoggedIn")
UserDefaults.standard.synchronize()

因此，当应用程序重新启动时，您需要检查用户是否已登录....并且基于此，您可以显示所需的屏幕......

if let isLoggedIn = UserDefaults.standard.value(forKey: "isUserLoggedIn") as? Bool, isLoggedIn == true {

   //Make root view controller
   UIStoryboard *mainStoryBoard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; 
   HomeViewController * hvc = [mainStoryBoard instantiateViewControllerWithIdentifier:@"HVC"];
   self.delegate.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:hvc];

} else {
    //show login view controller as user is not yet logged in
}

Answer 3

您要实现的是自动登录功能（如果用户已登录，则无需登录页面）。你正在做的是正确的，但你也需要从AppDelegate管理那件事设置根视图控制器

后，需要在代码中添加一行

        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isUserLoggedIn"]; 
        // PUT this line after  [self.delegate.window makeKeyAndVisible];

您可以在AppDelegate中创建方法，该方法监视来自UserDefault的布尔变量。并导航到vc1 - ＆gt; VC2

将其放入Appdelegate并从didFinishLuanchWithOptions

调用它

- (void) checkLoginStatusAndProceed {
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"isUserLoggedIn"] && [[NSUserDefaults standardUserDefaults] boolForKey:@"isUserLoggedIn"] == YES) {
        // Navigate to HomeViewController
        //Make root view controller
        UIStoryboard *mainStoryBoard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; //My storyboard name is Main.storyboard
        HomeViewController * hvc = [mainStoryBoard instantiateViewControllerWithIdentifier:@"HVC"];
        self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:hvc];
       [self.window makeKeyAndVisible];
    }

}

Answer 4

根据您的要求，您需要维护一个标志可能在UserDefaults。

注意：它只是伪代码，因为我不在笔记本电脑的桌面上

按照以下步骤操作：

创建用户默认对象并保存标记，例如isFirstLaunch = false
将HomeVC设置为root后，将此标志更改为true。
在didFinishLaunchingWithOptions的AppDelegate中，再次检查此标志，如

如果UserDefaults.standard.bool（for：＆＃34; isFirstLaunch＆＃34;）{ //显示登录 }其他{ //显示主页 }

设置根视图控制器不起作用？

4 个答案: