Flutter[desktop]：如何在没有文本字段的情况下从物理键盘获取输入？

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: RawKeyboardListener(
            focusNode: FocusNode(),
            onKey: (RawKeyEvent event) {
              if (event is RawKeyDownEvent) {
                // 处理按键事件
                if (event.logicalKey == LogicalKeyboardKey.enter) {
                  // 按下回车键
                  print('Enter key pressed');
                } else if (event.logicalKey == LogicalKeyboardKey.space) {
                  // 按下空格键
                  print('Space key pressed');
                }
              }
            },
            child: Container(
              width: 200,
              height: 200,
              color: Colors.grey,
              child: Center(
                child: Text(
                  'Press Enter or Space',
                  style: TextStyle(fontSize: 20),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}