如何在flutter中录制语音并将其存储到firebase存储中？

import 'package:flutter/material.dart';
import 'package:flutter_sound/flutter_sound.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:firebase_storage/firebase_storage.dart';

class VoiceRecorder extends StatefulWidget {
  @override
  _VoiceRecorderState createState() => _VoiceRecorderState();
}

class _VoiceRecorderState extends State<VoiceRecorder> {
  FlutterSoundRecorder? _recorder;
  bool _isRecording = false;

  @override
  void initState() {
    super.initState();
    _recorder = FlutterSoundRecorder();
  }

  Future<void> _startRecording() async {
    if (await Permission.microphone.request().isGranted) {
      await _recorder!.openAudioSession();
      await _recorder!.startRecorder(toFile: 'path_to_save_audio_file');
      setState(() {
        _isRecording = true;
      });
    }
  }

  Future<void> _stopRecording() async {
    await _recorder!.stopRecorder();
    await _recorder!.closeAudioSession();
    setState(() {
      _isRecording = false;
    });
    _uploadAudioFile('path_to_save_audio_file');
  }

  Future<void> _uploadAudioFile(String filePath) async {
    FirebaseStorage storage = FirebaseStorage.instance;
    Reference ref = storage.ref().child('audio').child('recording.wav');
    UploadTask uploadTask = ref.putFile(File(filePath));
    await uploadTask.whenComplete(() => print('File uploaded'));
  }

  @override
  void dispose() {
    _recorder!.closeAudioSession();
    _recorder = null;
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Voice Recorder'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            IconButton(
              icon: Icon(_isRecording ? Icons.stop : Icons.mic),
              onPressed: _isRecording ? _stopRecording : _startRecording,
            ),
            Text(_isRecording ? 'Recording...' : 'Tap to Record'),
          ],
        ),
      ),
    );
  }
}