在SwiftUI中以字符串形式检测键盘按键的iOS

import SwiftUI
import Combine

class KeyboardObserver: ObservableObject {
    @Published var key: String = ""
    
    init() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
    }
    
    @objc func keyboardWillShow(notification: Notification) {
        if let key = notification.userInfo?[UIResponder.keyboardIsLocalUserInfoKey] as? Bool, key {
            self.key = "Keyboard is shown"
        }
    }
    
    @objc func keyboardWillHide(notification: Notification) {
        if let key = notification.userInfo?[UIResponder.keyboardIsLocalUserInfoKey] as? Bool, key {
            self.key = "Keyboard is hidden"
        }
    }
}

struct ContentView: View {
    @ObservedObject var keyboardObserver = KeyboardObserver()
    
    var body: some View {
        VStack {
            Text(keyboardObserver.key)
                .padding()
            
            Spacer()
        }
        .onReceive(NotificationCenter.default.publisher(for: UIResponder.keyboardWillShowNotification)) { _ in
            self.keyboardObserver.keyboardWillShow(notification: Notification(name: UIResponder.keyboardWillShowNotification))
        }
        .onReceive(NotificationCenter.default.publisher(for: UIResponder.keyboardWillHideNotification)) { _ in
            self.keyboardObserver.keyboardWillHide(notification: Notification(name: UIResponder.keyboardWillHideNotification))
        }
    }
}