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

您可以使用接口生成器以及编程方式设置初始视图控制器。

下面是编程使用的方法。

objective - c:

        self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds];
        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];

        UIViewController *viewController = [storyboard instantiateViewControllerWithIdentifier:@"HomeViewController"]; // <storyboard id>

        self.window.rootViewController = viewController;
        [self.window makeKeyAndVisible];

        return YES;

迅速:

        self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

        var objMainViewController: MainViewController = mainStoryboard.instantiateViewControllerWithIdentifier("MainController") as! MainViewController

        self.window?.rootViewController = objMainViewController

        self.window?.makeKeyAndVisible()

        return true

其他回答

找到了简单的解决方案-不需要从故事板和编辑项目信息选项卡中删除“初始视图控制器检查”,并使用makeKeyAndVisible,只是放置

self.window.rootViewController = rootVC;

in

- (BOOL) application:didFinishLaunchingWithOptions:

使用Swift 3和Swift 4避免强制铸造的另一个解决方案是这样的

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
}

下面是使用UINavigationController

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
}

我认为这是不可能的。 相反,你可以有一个初始控制器它有segue到不同的视图控制器。在启动时,您可以决定以编程方式执行哪个segue。

斯威夫特5

如果你没有一个ViewController设置为storyboard中的初始ViewController,你需要做两件事:

进入你的项目TARGETS,选择你的项目-> General ->清除Main Interface字段。 总是在项目TARGETS中,现在转到Info ->应用场景清单->场景配置->应用程序会话角色-> Item0(默认配置)->删除故事板名称字段。

最后,你现在可以在SceneDelegate中添加你的代码:

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
    // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
    // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
    guard let windowScene = (scene as? UIWindowScene) else { return }

    window = UIWindow(windowScene: windowScene)


    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    // Make sure you set an Storyboard ID for the view controller you want to instantiate
    window?.rootViewController = storyboard.instantiateViewController(withIdentifier: identifier)
    window?.makeKeyAndVisible()

}

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()
    }