问SwiftUI TextField简单示例不起作用

EN

struct TextFieldExample : View {
    @State var email: String = "Enter email address"
    var body: some View {
        VStack {
            TextField($email)
            Text("Your email is \(email)!")
        }
    }
}

struct ButtonTextField : View {
    @State var text: String = ""

    var body: some View {
        HStack {
            TextField($text,
                      placeholder: Text("type something here..."))
            Button(action: {
                // Closure will be called once user taps your button
                print(self.$text)
            }) {
                Text("SEND")
            }
        }
    }
}