如何使用GetX Flutter在后台激活或最小化时获取应用程序状态

dependencies:
  flutter:
    sdk: flutter
  get: ^4.6.5

import 'package:get/get.dart';

class AppController extends GetxController with WidgetsBindingObserver {
  var appState = AppState.active.obs;

  @override
  void onInit() {
    super.onInit();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void onClose() {
    super.onClose();
    WidgetsBinding.instance.removeObserver(this);
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    switch (state) {
      case AppLifecycleState.resumed:
        appState.value = AppState.active;
        break;
      case AppLifecycleState.paused:
        appState.value = AppState.inactive;
        break;
      case AppLifecycleState.detached:
        appState.value = AppState.paused;
        break;
      default:
    }
  }
}

enum AppState { active, inactive, paused }

import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'app_controller.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return GetMaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomeScreen(),
      initialRoute: '/',
      getPages: [
        GetPage(name: '/', page: () => HomeScreen()),
      ],
      debugShowCheckedModeBanner: false,
    );
  }
}

class HomeScreen extends StatelessWidget {
  final AppController appController = Get.put(AppController());

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('App State Example'),
      ),
      body: Center(
        child: Obx(() => Text('App State: ${appController.appState.value}')),
      ),
    );
  }
}