从TextField字符串到模型的已发布可选整数属性的Swift和SwiftUI绑定

class MyModel: ObservableObject {
    @Published var intValue: Int?
}

struct ContentView: View {
    @ObservedObject var model = MyModel()
    @State private var textFieldString = ""

    var body: some View {
        VStack {
            TextField("Enter an integer", text: $textFieldString)
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .padding()

            Button("Save") {
                if let intValue = Int(textFieldString) {
                    model.intValue = intValue
                } else {
                    model.intValue = nil
                }
            }
        }
    }
}