dart - 扑腾的音频播放器

Question

在此处输入图像描述大家好，我在 Flutter 应用程序（XYLOPHONE 应用程序，在此捕获中）上播放声音时遇到问题。首先，当我按下每个播放不同声音的彩色按钮时，声音正常播放。但几秒钟后没有声音播放。这是 RUN 面板中带有错误消息的捕获。这是什么意思？？？

import 'package:flutter/material.dart';
import 'package:audioplayers/audio_cache.dart';

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

class XylophoneApp extends StatelessWidget {
  void soundNumber(int num) {
    final player = AudioCache();
    player.play('note$num.mp3');
  }

  Expanded playSound({Color color, int colorNumber}) {
    return Expanded(
      child: Container(
        child: FlatButton(
          onPressed: () {
            soundNumber(colorNumber);
          },
        ),
        color: color,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        backgroundColor: Colors.black,
        body: SafeArea(
          child: Center(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                playSound(color: Colors.purple, colorNumber: 1),
                playSound(color: Colors.indigo, colorNumber: 2),
                playSound(color: Colors.blue, colorNumber: 3),
                playSound(color: Colors.green, colorNumber: 4),
                playSound(color: Colors.yellow, colorNumber: 5),
                playSound(color: Colors.orange, colorNumber: 6),
                playSound(color: Colors.red, colorNumber: 7),
              ],
            ),
          ),
        ),
      ),
    );
  }
}