编辑：有关如何添加其他类似Windows面板的信息

要在Mac上支持多个窗口，您需要做的就是在iPad上支持多个窗口。

您可以在this WWDC会话开始的22:28分钟找到所有您需要的信息，但总结一下，您需要做的就是支持新的Scene生命周期模型。

首先编辑目标并选中支持多个窗口的选中标记

完成此操作后，单击配置选项，该选项会将您带到info.plist。 确保您有正确的Application Scene Manifest条目

创建一个名为SceneDelegate.swift的新swift文件，然后将以下样板代码粘贴到其中

import UIKit

class SceneDelegate: UIResponder,UIWindowSceneDelegate {

    var window: UIWindow?


    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).

        // Create the SwiftUI view that provides the window contents.
       guard let _ = (scene as? UIWindowScene) else { return }
    }

    func sceneDidDisconnect(_ scene: UIScene) {
        // Called as the scene is being released by the system.
        // This occurs shortly after the scene enters the background,or when its session is discarded.
        // Release any resources associated with this scene that can be re-created the next time the scene connects.
        // The scene may re-connect later,as its session was not neccessarily discarded (see `application:didDiscardSceneSessions` instead).
    }

    func sceneDidBecomeActive(_ scene: UIScene) {
        // Called when the scene has moved from an inactive state to an active state.
        // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
    }

    func sceneWillResignActive(_ scene: UIScene) {
        // Called when the scene will move from an active state to an inactive state.
        // This may occur due to temporary interruptions (ex. an incoming phone call).
    }

    func sceneWillEnterForeground(_ scene: UIScene) {
        // Called as the scene transitions from the background to the foreground.
        // Use this method to undo the changes made on entering the background.
    }

    func sceneDidEnterBackground(_ scene: UIScene) {
        // Called as the scene transitions from the foreground to the background.
        // Use this method to save data,release shared resources,and store enough scene-specific state information
        // to restore the scene back to its current state.
    }


}

您基本上完成了。运行您的应用程序，然后按Command + N创建所需数量的新窗口。

如果要在代码中创建新窗口，可以使用以下代码：

@IBAction func newWindow(_ sender: Any) {            
    UIApplication.shared.requestSceneSessionActivation(nil,userActivity: nil,options: nil) { (error) in
        //
    }
}

现在，我们开始深入了解如何创建其他窗口

此操作的关键是在应用程序中创建多种场景类型。您可以在无法正常工作的info.plist中或AppDelegate中进行操作。

让我们将函数更改为创建新窗口，以：

@IBAction func newWindow(_ sender: Any) {     
    var activity = NSUserActivity(activityType: "panel")
    UIApplication.shared.requestSceneSessionActivation(nil,userActivity: activity,options: nil) { (error) in

    }
}

为新场景创建一个新的故事板，至少创建一个视图控制器，并确保将其设置为故事板中的initalviewcontroller。

允许将以下功能添加到appdelegate：

func application(_ application: UIApplication,configurationForConnecting connectingSceneSession: UISceneSession,options: UIScene.ConnectionOptions) -> UISceneConfiguration { 
        if options.userActivities.first?.activityType == "panel" {
            let configuration = UISceneConfiguration(name: "Default Configuration",sessionRole: connectingSceneSession.role)
            configuration.delegateClass = CustomSceneDelegate.self
            configuration.storyboard = UIStoryboard(name: "CustomScene",bundle: Bundle.main)
            return configuration
        } else {
            let configuration = UISceneConfiguration(name: "Default Configuration",sessionRole: connectingSceneSession.role)
            configuration.delegateClass = SceneDelegate.self
            configuration.storyboard = UIStoryboard(name: "Main",bundle: Bundle.main)
            return configuration
        }
    }

通过在请求场景时设置userActivity，我们可以知道要创建哪个场景并相应地为其创建配置。菜单或CMD + N中的“新窗口”仍将创建您的默认新窗口，但是新窗口按钮现在将通过新的故事板创建UI。

塔达：

借助SwiftUI，您可以这样操作（感谢Ron Sebro）：

1。激活多个窗口支持：

2。请求一个新场景：

struct ContentView: View {
    var body: some View {
        VStack {
            // Open window type 1
            Button(action: {
                UIApplication.shared.requestSceneSessionActivation(nil,userActivity: NSUserActivity(activityType: "window1"),options: nil,errorHandler: nil)
            }) {
                Text("Open new window - Type 1")
            }

            // Open window type 2
            Button(action: {
                UIApplication.shared.requestSceneSessionActivation(nil,userActivity: NSUserActivity(activityType: "window2"),errorHandler: nil)
            }) {
                Text("Open new window - Type 2")
            }
        }
    }
}

3。创建新的窗口视图：

struct Window1: View {
    var body: some View {
        Text("Window1")
    }
}

struct Window2: View {
    var body: some View {
        Text("Window2")
    }
}

4。更改SceneDelegate.swift：

    func scene(_ scene: UIScene,options connectionOptions: UIScene.ConnectionOptions) {
        if let windowScene = scene as? UIWindowScene {
            let window = UIWindow(windowScene: windowScene)

            if connectionOptions.userActivities.first?.activityType == "window1" {
                window.rootViewController = UIHostingController(rootView: Window1())
            } else if connectionOptions.userActivities.first?.activityType == "window2" {
                window.rootViewController = UIHostingController(rootView: Window2())
            } else {
                window.rootViewController = UIHostingController(rootView: ContentView())
            }

            self.window = window
            window.makeKeyAndVisible()
        }
    }