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.
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)
There is an extension:
extension UIViewController {
/// Add a SwiftUI `View` as a child of the input `UIView`.
/// - Parameters:
/// - swiftUIView: The SwiftUI `View` to add as a child.
/// - view: The `UIView` instance to which the view should be added.
func addSwiftUIbodyView<Content>(_ swiftUIView: Content, to view: UIView) where Content: View {
let hostingController = UIHostingController(rootView: swiftUIView)
/// Add as a child of the current view controller.
addChild(hostingController)
/// Add the SwiftUI view to the view controller view hierarchy.
view.addSubview(hostingController.view)
/// Setup the contraints to update the SwiftUI view boundaries.
hostingController.view.translatesAutoresizingMaskIntoConstraints = false
let constraints = [
hostingController.view.topAnchor.constraint(equalTo: view.topAnchor),
hostingController.view.leftAnchor.constraint(equalTo: view.leftAnchor),
view.bottomAnchor.constraint(equalTo: hostingController.view.bottomAnchor),
view.rightAnchor.constraint(equalTo: hostingController.view.rightAnchor)
]
NSLayoutConstraint.activate(constraints)
/// Notify the hosting controller that it has been moved to the current view controller.
hostingController.didMove(toParent: self)
}
}