I am new to swiftUI. I want to add swiftUI view in my current UIkit project for which I created a demo in which I m stuck now.

Here is my ViewController in code :

import UIKit
import SwiftUI

class ViewController: UIViewController {
    
    
    @IBOutlet weak var stepperContenerView: UIView!
    @IBOutlet weak var btn:UIButton!
    
    
    lazy var stepView = StepperView(intialCount: 1)
    lazy var swiftUIHostingView = UIHostingController(rootView: stepView)
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        stepperContenerView.addSubview(swiftUIHostingView.view)
        addChild(swiftUIHostingView)
//        stepView.delegate = self

        swiftUIHostingView.view.frame = stepperContenerView.bounds
        stepperContenerView.addConstrained(subview: swiftUIHostingView.view)
        swiftUIHostingView.didMove(toParent: self)
    }
    @IBAction func onClickBtn(_ sender: UIButton) {
        let alert = UIAlertController(title: "Stepper count", message: "Current value : \(stepView.getCount())", preferredStyle: UIAlertController.Style.alert)
        alert.addAction(UIAlertAction(title: "ok", style: UIAlertAction.Style.default, handler: nil))
        self.present(alert, animated: true, completion: nil)
    } 
}
 
//extension ViewController:OnClickStepperButton {
//    func updateCount(count: Int) {
//        print("Test")
//        lbl.text = "Stepper count is - \(count)"
//    }
//}

and here is my code for swiftUI stepper view:-

import SwiftUI

protocol OnClickStepperButton {
    func updateCount(count:Int)
}

struct StepperView: View {
    @State private var count:Int = 1
    var delegate:OnClickStepperButton?
    
    init(intialCount:Int){
        self.count = intialCount
    }
    
    var body: some View {
        HStack(alignment: .center, spacing: 10) {
            Button(" ", action: {
                count  = 1
                print(count)
//                delegate?.updateCount(count: count)
            })
            
            Text("\(count)")
                .frame(minWidth: 40,minHeight: 40)
                .background(Color.white)
                .foregroundColor(.black)
                .scaledToFill()
                
            Button("-", action: {
                if count > 1 {
                    count -= 1
                    print(count)
                }
//                delegate?.updateCount(count: count)
            })
            
        }
        .font(.system(size: 22, weight: .medium, design: .serif))
        .frame(minWidth: 120, minHeight: 40, alignment: .center)
        .background(Color.blue)
        .foregroundColor(Color.white)
        .cornerRadius(20)
    
    }
    public func getCount() -> Int {
        count
    }

}

struct Stepper_Previews: PreviewProvider {
    static var previews: some View {
        StepperView(intialCount: 1)
            .previewLayout(.fixed(width: 300, height: 70))
    }
}

Neither the delegate are calling, nor I m getting update value value on clicking of the button. (delegate are comment on purpose for highlighting its not working kindly uncomment it to check).

CodePudding user response：

The delegate Variable never gets set as is.

You need to remove the ? From the variable in the SwiftUI view so you are forced to provide a value upon init.

Also, remove the custom initializer.