ios - 如何根据用户是否登录来处理在应用程序启动时显示不同的 View Controller ？

Question

在我正在开发的应用程序中，我需要在应用程序启动时根据用户是否登录显示不同的 View Controller

• 如果用户已经登录，我需要显示HomeViewController
• 如果用户没有登录，我需要显示LoginViewController

目前，我的编码方式如下-

• AppDelegate 的 window 的 rootViewController 始终嵌入 UINavigationController 中的 LoginViewController .

• 在 LoginViewController 的 viewDidAppear 方法中，我检查用户是否已登录。如果是，则推送 HomeViewController .

• 在 HomeViewController 中，当用户注销时，我弹出 HomeViewController 以显示 LoginViewController

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有更好的方法吗？

Answer 1

哪种方法更好，完全取决于您的要求和 self 满意度。

现在考虑一下您的方法:

• If you're going with this approach then login screen will display for fraction of time. If it is okay for you then you can for it.

现在想想我的方法:

• I think the better way is to check the same condition in didFinishLaunchingWithOptions instead of loginVC
• If you are going this approach then your HomeVC is directly displayed after your splash screen. It is the main advantage of this approach

代码:

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

    let isLoggedIn = true
    let storyboard = UIStoryboard.init(name: "Main", bundle: nil)
    let navigationController = storyboard.instantiateViewController(withIdentifier: "NavigationController") as! UINavigationController

    var viewController:UIViewController

    if !isLoggedIn{
        viewController = storyboard.instantiateViewController(withIdentifier: "LoginVC")
    }else{
        viewController = storyboard.instantiateViewController(withIdentifier: "HomeVC")
    }

    navigationController.viewControllers = [viewController]
    window?.rootViewController = navigationController

    return true
}

Download sample code

Anbu.Karthik 更新:

只需在 AppDelegate.swift 文件中定义方法，然后在需要时调用它。此外，示例代码中也实现了相同的方法。

let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.logoutFromApp()

更改 Root View Controller 的代码:

func logoutFromApp(){
    guard let rootNavigationController = window?.rootViewController as? UINavigationController else {
        return
    }
    let storyboard = UIStoryboard.init(name: "Main", bundle: nil)
    let viewController = storyboard.instantiateViewController(withIdentifier: "LoginVC")
    rootNavigationController.viewControllers = [viewController]
}