SwiftUI in UIKit.swift

import UIKit
// 1. Import SwiftUI
import SwiftUI

class ViewController: UIViewController {
  
  override func viewDidLoad() {
    super.viewDidLoad()
    // 2. Initialize SwiftUI View
    let image = Image(
      systemName: "star.fill"
    )
      .resizable()
      .foregroundColor(.red)
    
    // 3. Create a UIHostingController to wrap SwiftUI view
    let hostingController = UIHostingController(
      rootView: image
    )
    
    // 4. Add hosting to Parent View and ViewController
    self.addChild(hostingController)
    self.view.addSubview(hostingController.view)
    hostingController.didMove(toParent: self)
    
    // 5. Position and size
    let swiftuiView = hostingController.view!
    swiftuiView.translatesAutoresizingMaskIntoConstraints = false
    let horizontalConstraint = swiftuiView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
    let verticalConstraint = swiftuiView.centerYAnchor.constraint(equalTo: view.centerYAnchor)
    let widthConstraint = swiftuiView.widthAnchor.constraint(equalToConstant: 200)
    let heightConstraint = swiftuiView.heightAnchor.constraint(equalToConstant: 200)
    view.addConstraints([
      horizontalConstraint,
      verticalConstraint,
      widthConstraint,
      heightConstraint
    ])
  }
}