使用故事板编程设置初始视图控制器

Question

使用故事板编程设置初始视图控制器

iosobjective-cswiftuiviewcontrolleruistoryboard

267

我如何以编程的方式设置Storyboard中的InitialViewController？我想根据某些条件，在每次启动时打开Storyboard的不同视图。

- Jagdev Sendhav

1

请查看此答案，无需在设置中清除主故事板或警告。链接 - Borzh

25个回答

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- abdullahselek · Answer 1

使用Swift 3和Swift 4的另一个解决方案是避免强制转换，具体如下：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    self.window = UIWindow(frame: UIScreen.main.bounds)
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    guard let viewController = storyboard.instantiateViewController(withIdentifier: "YourViewController") as? YourViewController else {
        return false
    }
    self.window?.rootViewController = viewController
    self.window?.makeKeyAndVisible()
    return true
}

以下是使用 UINavigationController 的内容：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    self.window = UIWindow(frame: UIScreen.main.bounds)
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    guard let viewController = storyboard.instantiateViewController(withIdentifier: "YourViewController") as? YourViewController else {
        return false
    }
    let navigationController = UINavigationController(rootViewController: viewController)
    self.window?.rootViewController = navigationController
    self.window?.makeKeyAndVisible()
    return true
}

- Nedim Talovic · Answer 2

在AppDelegate.swift文件中，您可以添加以下代码：

let sb = UIStoryboard(name: "Main", bundle: nil)
let vc = sb.instantiateViewController(withIdentifier: "YourViewController_StorboardID")
self.window?.rootViewController = vc
self.window?.makeKeyAndVisible()

当然，您需要根据哪些条件选择合适的视图控制器来实现您的逻辑。

此外，请不要忘记添加标识（选择故事板 -> 控制器场景 -> 显示“身份检查器” -> 分配StoryboardID）。

- Varun Naharia · Answer 3

我创建了一个路由类来处理动态导航并保持AppDelegate类的整洁，希望它也能帮助其他人。

//
//  Routing.swift
// 
//
//  Created by Varun Naharia on 02/02/17.
//  Copyright © 2017 TechNaharia. All rights reserved.
//

import Foundation
import UIKit
import CoreLocation

class Routing {

    class func decideInitialViewController(window:UIWindow){
        let userDefaults = UserDefaults.standard
        if((Routing.getUserDefault("isFirstRun")) == nil)
        {
            Routing.setAnimatedAsInitialViewContoller(window: window)
        }
        else if((userDefaults.object(forKey: "User")) != nil)
        {
            Routing.setHomeAsInitialViewContoller(window: window)
        }
        else
        {
            Routing.setLoginAsInitialViewContoller(window: window)
        }

    }

    class func setAnimatedAsInitialViewContoller(window:UIWindow) {
        Routing.setUserDefault("Yes", KeyToSave: "isFirstRun")
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let animatedViewController: AnimatedViewController = mainStoryboard.instantiateViewController(withIdentifier: "AnimatedViewController") as! AnimatedViewController

        window.rootViewController = animatedViewController
        window.makeKeyAndVisible()
    }

    class func setHomeAsInitialViewContoller(window:UIWindow) {
        let userDefaults = UserDefaults.standard
        let decoded  = userDefaults.object(forKey: "User") as! Data
        User.currentUser = NSKeyedUnarchiver.unarchiveObject(with: decoded) as! User

        if(User.currentUser.userId != nil && User.currentUser.userId != "")
        {
            let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
            let homeViewController: HomeViewController = mainStoryboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
            let loginViewController: UINavigationController = mainStoryboard.instantiateViewController(withIdentifier: "LoginNavigationViewController") as! UINavigationController
            loginViewController.viewControllers.append(homeViewController)
            window.rootViewController = loginViewController
        }
        window.makeKeyAndVisible()
    }

    class func setLoginAsInitialViewContoller(window:UIWindow) {
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let loginViewController: UINavigationController = mainStoryboard.instantiateViewController(withIdentifier: "LoginNavigationViewController") as! UINavigationController

        window.rootViewController = loginViewController
        window.makeKeyAndVisible()
    }

  class func setUserDefault(_ ObjectToSave : Any?  , KeyToSave : String)
    {
        let defaults = UserDefaults.standard

        if (ObjectToSave != nil)
        {

            defaults.set(ObjectToSave, forKey: KeyToSave)
        }

        UserDefaults.standard.synchronize()
    }

    class func getUserDefault(_ KeyToReturnValye : String) -> Any?
    {
        let defaults = UserDefaults.standard

        if let name = defaults.value(forKey: KeyToReturnValye)
        {
            return name as Any
        }
        return nil
    }

    class func removetUserDefault(_ KeyToRemove : String)
    {
        let defaults = UserDefaults.standard
        defaults.removeObject(forKey: KeyToRemove)
        UserDefaults.standard.synchronize()
    }

}

在您的AppDelegate中调用以下内容：

 self.window = UIWindow(frame: UIScreen.main.bounds)
 Routing.decideInitialViewController(window: self.window!)

- Shan Ye · Answer 4

在文件AppDelegate.swift中，Swift 4，Xcode 9。

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let firstVC = storyboard.instantiateViewController(withIdentifier: "firstViewController") as! firstViewController
    self.window?.rootViewController = firstVC
}

- V D Purohit · Answer 5

let mainStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc = mainStoryboard.instantiateViewController(withIdentifier: "storyBoardid") as! ViewController
let navigationController = UINavigationController(rootViewController: vc)
UIApplication.shared.delegate.window?.rootViewController = navigationController

另一种方法是展示视图控制器（viewController）。

let mainStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc = mainStoryboard.instantiateViewController(withIdentifier: "storyBoardid") as! ViewController
self.present(vc,animated:true,completion:nil)

首先，您需要创建故事板对象，然后更改根（如果需要），然后获取特定视图控制器的引用，该视图控制器推送了当前视图控制器（如果更改了根）；否则，它只是呈现新的视图控制器，这可能是您所需的。

- alex1704 · Answer 6

我发现了一个简单的解决方案——无需从故事板中删除“初始视图控制器检查”，也不需要编辑项目信息选项卡并使用makeKeyAndVisible，只需将

self.window.rootViewController = rootVC;

在

- (BOOL) application:didFinishLaunchingWithOptions:

- Jeremy · Answer 7

感谢您在AppDelegate中进行以下修改：

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) ->     Bool {
//Some code to check value of pins

if pins! == "Verified"{
        print(pins)
        self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "HomePage", bundle: nil)
        let exampleViewController: UINavigationController = mainStoryboard.instantiateViewControllerWithIdentifier("SBHP") as! UINavigationController

        self.window?.rootViewController = exampleViewController

        self.window?.makeKeyAndVisible()
    }else{
        print(pins)
        self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let exampleViewController: UINavigationController = mainStoryboard.instantiateViewControllerWithIdentifier("SBUser") as! UINavigationController

        self.window?.rootViewController = exampleViewController

        self.window?.makeKeyAndVisible()
    }

- m.etka · Answer 8

几天前我遇到了同样的情况。一个非常简单的技巧解决了这个问题。在启动2之前，我隐藏了我的初始视图控制器。如果初始视图控制器是正确的控制器，则在viewDidLoad中将其设置为可见。否则，将执行一个segue到所需的视图控制器。它在iOS 6.1及以上版本上完美运行。我确信它也适用于早期版本的iOS。

- Kamen Dobrev · Answer 9

如果您不想更改applicationDidFinish方法，您可以使用以下小技巧：
将导航控制器设置为初始视图控制器，并将其分配给自定义类'MyNavigationController'。然后，在viewDidLoad期间调整其根视图控制器-它将覆盖您在故事板中设置的根视图控制器。

class MyNavigationController: UINavigationController {
    override func viewDidLoad() {
        super.viewDidLoad()
        if !isLoggedIn() {
            viewControllers = [R.storyboard.authentication.loginView()!]
        }
    }

    private func isLoggedIn() -> Bool {
        return false
    }

}

- charles · Answer 10

 func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        self.window = UIWindow(frame: UIScreen.main.bounds)
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        if (PreferenceHelper.getAccessToken() != "") {
            let initialViewController = storyboard.instantiateViewController(withIdentifier: "your View Controller Identifier")
            self.window?.rootViewController = initialViewController
        } else {
            let initialViewController = storyboard.instantiateViewController(withIdentifier: "your View Controller identifier")
            self.window?.rootViewController = initialViewController
        }
        self.window?.makeKeyAndVisible()
        return true
    }

/*
use your view Controller identifier must use it doubles quotes**strong text**