我认为你必须在键盘上方增加一个按钮，叫做工具栏按钮
希望这能有所帮助

struct ContentView: View {
private enum Field: Int, CaseIterable {
    case username
}

@State private var username: String = ""

@FocusState private var focusedField: Field?

var body: some View {
    NavigationView {
            TextField("Username", text: $username)
                .focused($focusedField, equals: .username)
        .toolbar {
            ToolbarItem(placement: .keyboard) {
                Button("Done") {
                    focusedField = nil
                }
            }
        }
    }
}}