I'm following this tutorial:

https://www.youtube.com/watch?v=aWL7W8SLfeo

...on importing a SwiftUI file into an existing Storyboard project. When it didn't work in my existing project I made a brand new one from scratch (Xcode 13.2.1) and it doesn't seem to matter. When I click the link to go to the ViewController hosting the view... it still comes up blank.

The Hosting ViewController:

import UIKit
import SwiftUI

class PokeViewController: UIViewController {

    @IBOutlet weak var theContainer: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()

        let childView = UIHostingController(rootView: SwiftUIView())
        addChild(childView)
        theContainer.addSubview(childView.view)
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destination.
        // Pass the selected object to the new view controller.
    }
    */

}

The SwiftUI:

import SwiftUI

struct SwiftUIView: View {
    var body: some View {
        Text(/*@START_MENU_TOKEN@*/"Hello, World!"/*@END_MENU_TOKEN@*/)
    }
}

struct SwiftUIView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIView()
    }
}

Here's the AppDelegate and SceneDelegate if that helps:

import UIKit

@main
class AppDelegate: UIResponder, UIApplicationDelegate {



    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        return true
    }

    // 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.
    }


}

SceneDelegate

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).
        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 necessarily 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.
    }


}

The PokeViewController class is connected to the correct ViewController in the storyboard... and the SwiftUIView is connected to the view. But when I visit PokeViewController... it's just blank (though I KNOW any code I have is being run. If I do something like an ImagePicker and set its default launch to "True"... it launches... and I can see the images... but once I'm done or click cancel it's back to the same blank page.)

Any help would be appreciated.

CodePudding user response：

Try to add after

theContainer.addSubview(childView.view)

following code:

childView.view.translatesAutoresizingMaskIntoConstraints = false
let constraints = [
    childView.view.topAnchor.constraint(equalTo: theContainer.topAnchor),
    childView.view.leftAnchor.constraint(equalTo: theContainer.leftAnchor),
    theContainer.bottomAnchor.constraint(equalTo: childView.view.bottomAnchor),
    theContainer.rightAnchor.constraint(equalTo: childView.view.rightAnchor)
]

NSLayoutConstraint.activate(constraints)

/// Notify the hosting controller that it has been moved to the current view controller.
childView.didMove(toParent: self)