我如何以编程方式设置一个故事板的InitialViewController ?我想打开我的故事板到一个不同的视图这取决于不同的启动条件。


当前回答

谢谢在AppDelegate中修改如下:

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()
    }

其他回答

我创建了一个路由类来处理动态导航和保持干净的AppDelegate类,我希望它也能帮助其他。

//
//  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AppDelegate中调用这个

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

你可以将Navigation rootviewcontroller设置为一个主视图控制器。 这个想法可以用于根据应用程序需求自动登录。

UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle: nil];

UIViewController viewController = (HomeController*)[mainStoryboard instantiateViewControllerWithIdentifier: @"HomeController"];

UINavigationController navController = [[UINavigationController alloc] initWithRootViewController:viewController];

 self.window.rootViewController = navController;

if (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_6_1) {

    // do stuff for iOS 7 and newer

    navController.navigationBar.barTintColor = [UIColor colorWithRed:88/255.0 green:164/255.0 blue:73/255.0 alpha:1.0];

    navController.navigationItem.leftBarButtonItem.tintColor = [UIColor colorWithRed:88/255.0 green:164/255.0 blue:73/255.0 alpha:1.0];

    navController.navigationBar.tintColor = [UIColor whiteColor];

    navController.navigationItem.titleView.tintColor = [UIColor whiteColor];

    NSDictionary *titleAttributes =@{

                                     NSFontAttributeName :[UIFont fontWithName:@"Helvetica-Bold" size:14.0],

                                     NSForegroundColorAttributeName : [UIColor whiteColor]

                                     };

    navController.navigationBar.titleTextAttributes = titleAttributes;

    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

}

else {

    // do stuff for older versions than iOS 7

    navController.navigationBar.tintColor = [UIColor colorWithRed:88/255.0 green:164/255.0 blue:73/255.0 alpha:1.0];



    navController.navigationItem.titleView.tintColor = [UIColor whiteColor];

}

[self.window makeKeyAndVisible];

对于StoryboardSegue用户

UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle: nil];

// Go to Login Screen of story board with Identifier name : LoginViewController_Identifier

LoginViewController *loginViewController = (LoginViewController*)[mainStoryboard instantiateViewControllerWithIdentifier:@“LoginViewController_Identifier”];

navigationController = [[UINavigationController alloc] initWithRootViewController:testViewController];

self.window.rootViewController = navigationController;

[self.window makeKeyAndVisible];

// Go To Main screen if you are already Logged In Just check your saving credential here

if([SavedpreferenceForLogin] > 0){
    [loginViewController performSegueWithIdentifier:@"mainview_action" sender:nil];
}

谢谢

如果你在iOS 13+中使用场景委托:

在你的信息中确认。Plist文件你发现行在:

Application Scene Manifest > Scene Configuration > Application Session Role > Item 0

并在那里删除对Main Storyboard的引用。否则,您将得到关于从storyboard实例化失败的相同警告。

同样,将代码从应用程序委托移动到场景委托方法scene(_:willConnectTo:options:),因为这是现在处理生命周期事件的地方。

选择要首先打开的视图控制器,然后转到属性检查器。 转到初始场景,检查初始视图控制器选项。

这是你的初始视图控制器在应用启动时首先打开。

Xcode 12.4 Swift 5

在SceneDelegate.Swift

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    guard let windowScene = (scene as? UIWindowScene) else { return }
    let window = UIWindow(windowScene: windowScene)
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    window.rootViewController = storyboard.instantiateViewController(withIdentifier: "UserViewController") as! UserViewController
    
    self.window = window
    window.makeKeyAndVisible()
}

你可以添加视图控制器场景将要显示的条件