使用 SceneDelegate 在 AppDelegate 中设置 UIWindow

Question

I was trying to init var window: UIWindow? to a UIViewController programmatically in AppDelegate .But I cannot achieve it. When I was updated my Xcode to Version 11.0 (11A420a) , in project init section, I choosed to with Storyboard not to SwiftUI but I can not achieved to programmatically assign the UIWindow's rootViewController to a view controller. So first of all, I removed the Main.storyboard file, then I hang with Info.plist and removed the storyboard section as usual like I do before but there's some configs about UIApplicationSceneManifest as shown below. And

<key>UIApplicationSceneManifest</key>
    <dict>
        <key>UIApplicationSupportsMultipleScenes</key>
        <false/>
        <key>UISceneConfigurations</key>
        <dict>
            <key>UIWindowSceneSessionRoleApplication</key>
            <array>
                <dict>
                    <key>UISceneConfigurationName</key>
                    <string>Default Configuration</string>
                    <key>UISceneDelegateClassName</key>
                    <string>$(PRODUCT_MODULE_NAME).SceneDelegate</string>
                </dict>
            </array>
        </dict>
    </dict>

By the way, for checking out what happens, I tried the init window in SceneDelegate.swift and AppDelegate.swift file but simulator's screen shows black screen fully. So what I must to do?

Hint: var window: UIWindow! variable description is not added to AppDelegate default anymore, its in SceneDelegate . So can I set my rootViewController from SceneDelegate file?

What's the way to achieve fully programmatically this in the new AppDelegate/SceneDelegate approach?

Answer 1

In AppDelegate I removed the lines which contains functions of UISceneSession Lifecyle then it worked it.

// MARK: UISceneSession Lifecycle

 func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
        // Called when a new scene session is being created.
        // Use this method to select a configuration to create the new scene with.
        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    }

    func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {
        // Called when the user discards a scene session.
        // If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
        // Use this method to release any resources that were specific to the discarded scenes, as they will not return.
    }

Than add var window: UIWindow? property to AppDelegate and inited it and set rootViewController programmatically, then worked it but for detail information, I will edit my answer as soon as I learned about UIScene workflow.