MacOS Swiftui发送模拟器键盘事件

Question

每个人：

我只是开发一个MacOS桌面应用程序，我创建一个按钮，然后单击模拟器keyborad事件发送一些char，例如a 到上面的文本字段，但不起作用。有帮助吗？

struct ContentView: View {
    @State private var username: String = ""
    @FocusState private var emailFieldIsFocused: Bool
    
    var body: some View {
        VStack {
            TextField(
                    "User name (email address)",
                    text: $username
                )
                .focused($emailFieldIsFocused)
                .onSubmit {
                    
                }
                .disableAutocorrection(true)
                .border(.secondary)
            Button {
                print("button clicked")
                let src = CGEventSource(stateID: CGEventSourceStateID.hidSystemState)

                let eventDown = CGEvent(keyboardEventSource: src, virtualKey: UInt16(0), keyDown: true)
                eventDown?.post(tap: .cghidEventTap)
                
                let eventUp = CGEvent(keyboardEventSource: src, virtualKey: UInt16(0), keyDown: false)
                eventUp?.post(tap: .cghidEventTap)
                
                
            } label: {
                Text("click me")
            }.padding()
        }
        
    }

我希望将键盘输入a仿真到文本字段，然后单击按钮，但无需发送。

app ui img