In what scenarios is it appropriate to use UIHostingController in an app?

UIHostingController is used to integrate SwiftUI into UIKit applications. This is especially useful when you need to:

• Embed a SwiftUI view into an existing UIKit controller.
• Gradually migrate an app from UIKit to SwiftUI.
• Use the advantages of SwiftUI (e.g., declarative UI) without a complete overhaul of the app.

Example of usage:

import SwiftUI
import UIKit

struct MySwiftUIView: View {
    var body: some View {
        Text("Hello from SwiftUI")
    }
}

class MyViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let swiftUIView = MySwiftUIView()
        let hostingController = UIHostingController(rootView: swiftUIView)
        addChild(hostingController)
        hostingController.view.frame = view.bounds
        view.addSubview(hostingController.view)
        hostingController.didMove(toParent: self)
    }
}

Thus, UIHostingController acts as a bridge between UIKit and SwiftUI.