SwiftUI Coordinator: method can not be marked @objc

Question

Using a UIViewController in SwiftUI I need to assign selectors for two buttons. Those need to be @objc but I get the error:

Method cannot be marked @objc because the type of the parameter cannot be represented in Objective-C

struct ScanPreView: UIViewControllerRepresentable {

    class Coordinator: NSObject {
        
        var parent: ScanPreView
        
        init(_ parent: ScanPreView) {
            self.parent = parent
        }
        
        @objc func dismissPreviewedScanTapped(sender: ScanPreView) {
            
        }
        
        @objc func savePreviewedSceneTapped(sender: ScanPreView) {
            
        }
    }
        
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    func makeUIViewController(context: Context) -> ScenePreviewViewController {
        let preview = ScenePreviewViewController(pointCloud: pointCloud, meshTexturing: meshTexturing, landmarks: nil)
        preview.leftButton.addTarget(context.coordinator, action: #selector(Coordinator.dismissPreviewedScanTapped(sender:)), for: UIControl.Event.touchUpInside)
        preview.rightButton.addTarget(context.coordinator, action: #selector(Coordinator.savePreviewedSceneTapped(sender:)), for: UIControl.Event.touchUpInside)
        return preview
    }
}

https://stackoverflow.com/questions/26173234/how-to-use-swift-struct-in-objective-c — Ol Sen, Oct 28 '20 at 14:28

score 2 · Accepted Answer · answered Oct 28 '20 at 14:28

2

You don't need view there, so just use Any if you need action signature, like

@objc func dismissPreviewedScanTapped(sender: Any) {
    
}

answered Oct 28 '20 at 14:28

Asperi

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as swift structs can not be exposed to objC, a simple and easy solution. – Ol Sen Oct 28 '20 at 14:32

SwiftUI Coordinator: method can not be marked @objc

1 Answers1