播放从webview_flutter加载的html页面链接的位于ApplicationSupportDirectory (不是资源目录)中的mp3文件

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:path_provider/path_provider.dart';
import 'package:flutter_sound/flutter_sound.dart';

class WebViewAudioPlayer extends StatefulWidget {
  final String audioUrl;

  WebViewAudioPlayer({required this.audioUrl});

  @override
  _WebViewAudioPlayerState createState() => _WebViewAudioPlayerState();
}

class _WebViewAudioPlayerState extends State<WebViewAudioPlayer> {
  late FlutterSoundPlayer _audioPlayer;
  late String _localFilePath;

  @override
  void initState() {
    super.initState();
    _audioPlayer = FlutterSoundPlayer();
    _localFilePath = '';
    _downloadAudioFile();
  }

  @override
  void dispose() {
    _audioPlayer.release();
    super.dispose();
  }

  Future<void> _downloadAudioFile() async {
    final response = await http.get(Uri.parse(widget.audioUrl));
    final appSupportDir = await getApplicationSupportDirectory();
    final audioFile = await File('${appSupportDir.path}/audio.mp3').create();
    await audioFile.writeAsBytes(response.bodyBytes);
    setState(() {
      _localFilePath = audioFile.path;
    });
  }

  Future<void> _playAudio() async {
    await _audioPlayer.openAudioSession();
    await _audioPlayer.startPlayer(
      fromURI: _localFilePath,
      codec: Codec.mp3,
    );
  }

  Future<void> _stopAudio() async {
    await _audioPlayer.stopPlayer();
    await _audioPlayer.closeAudioSession();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('WebView Audio Player'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            ElevatedButton(
              onPressed: _localFilePath.isNotEmpty ? _playAudio : null,
              child: Text('Play Audio'),
            ),
            SizedBox(height: 16),
            ElevatedButton(
              onPressed: _localFilePath.isNotEmpty ? _stopAudio : null,
              child: Text('Stop Audio'),
            ),
          ],
        ),
      ),
    );
  }
}