Has anyone seen this Generic class 'UIHostingController' requires that 'ContentView' conform to 'View'

Question

getting a compile time error that states: Generic class 'UIHostingController' requires that 'ContentView' conform to 'View'

I tried looking into typecasting and I didn't find anything useful in my searches

XCODE 11.5 my 1st iOS app nun fancy only one view and the two Delegate files , im getting this error, don't understand why, its stock code do you type cast? how ? help xcode sucks : (

SceneDelegate:

//  SceneDelegate.swift
//  PlayDaGang4
//
//  Created by dfds on 6/21/20.
//  Copyright © 2020 dfds. All rights reserved.
//

import UIKit
import SwiftUI

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.
        let contentView = ContentView()

        // Use a UIHostingController as window root view controller.
        if let windowScene = scene as? UIWindowScene {
            let window = UIWindow(windowScene: windowScene)
            window.rootViewController = UIHostingController(rootView: contentView)
            self.window = window
            window.makeKeyAndVisible()
        }
    }

    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.
    }


}

ContentView:

import MediaPlayer


class ContentView: UIViewController {

    var musicPlayer = MPMusicPlayerController.applicationMusicPlayer
    
    override func viewDidLoad() {
        super.viewDidLoad()

  
    }
    
    @IBAction func stopButtonTapped(_ sender: UIButton) {
        musicPlayer.stop()
    }
    @IBAction func nextButtonTapped(_ sender: UIButton) {
        musicPlayer.skipToNextItem()
    }
    @IBAction func previousButtonTapped(_ sender: UIButton) {
        musicPlayer.skipToPreviousItem()
    }
    @IBAction func musicButtonTapped(_ sender: UIButton) {
        
        MPMediaLibrary.requestAuthorization {(status) in
            if status == .authorized{
                self.playArtist(artist: sender.currentTitle!)
            }
        }
        
        playArtist(artist: sender.currentTitle!)
    }
    
    func playArtist (artist: String){
        
        musicPlayer.stop();
        
        let query = MPMediaQuery()
        let predicate = MPMediaPropertyPredicate(value: artist, forProperty: MPMediaItemPropertyArtist)
        query.addFilterPredicate(predicate)
        musicPlayer.setQueue(with: query)
        musicPlayer.shuffleMode = .songs
        musicPlayer.play()
    }
    
}

Answer 1

You're trying to set a class that inherits from UIViewController as rootView of UIHostingController. rootView of UIHostingController always has to conform to View protocol. If you're trying to use a UIViewController as rootViewController then set it directly in SceneDelegate. To fix your issue

Replace this:

window.rootViewController = UIHostingController(rootView: contentView)

With this:

window.rootViewController = contentView

Note: It's better to follow standards when your naming your declarations, change ContentView -> ContentViewController.