问在颤振中，如果耳机突然插上电源，我如何才能检测到这种变化？

EN

import 'package:flutter/material.dart';
import 'package:headset_connection_event/headset_event.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final _headsetPlugin = HeadsetEvent();
  HeadsetState? _headsetState;

  @override
  void initState() {
    super.initState();

    /// if headset is plugged
    _headsetPlugin.getCurrentState.then((_val) {
      setState(() {
        _headsetState = _val;
      });
    });

    /// Detect the moment headset is plugged or unplugged
    _headsetPlugin.setListener((_val) {
      setState(() {
        _headsetState = _val;
      });
    });
  }

  @override
  Widget build(BuildContext context) => MaterialApp(
        home: Scaffold(
          appBar: AppBar(
            title: const Text('Headset Event Plugin'),
          ),
          body: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Icon(
                  Icons.headset,
                  color: this._headsetState == HeadsetState.CONNECT ? Colors.green : Colors.red,
                ),
                Text('State : $_headsetState\n'),
              ],
            ),
          ),
        ),
      );
}