main.dart

import 'package:flutter/material.dart';
import 'package:audio_service/audio_service.dart';

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

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

class _MyAppState extends State<MyApp> with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    connect();
  }

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

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    switch (state) {
      case AppLifecycleState.resumed:
        connect();
        break;
      case AppLifecycleState.paused:
        AudioService.disconnect();
        break;
      default:
        break;
    }
  }

  void connect() {
    AudioService.connect();
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: const Text('Audio Service Demo'),
        ),
        body: Center(
          child: RaisedButton(
            child: Text('ADD TO QUEUE'),
            onPressed: () async {
              await AudioService.start(
                backgroundTask: _backgroundAudioPlayerTask,
                resumeOnClick: true,
                notificationChannelName: 'Audio Service Demo',
                notificationColor: 0xFF2196f3,
                androidNotificationIcon: 'mipmap/ic_launcher',
              );
              MediaItem mediaItem = MediaItem(
                  id: 'audio_1', album: 'Sample Album', title: 'Sample Title');
              AudioService.addQueueItem(mediaItem);
            },
          ),
        ),
      ),
    );
  }
}

void _backgroundAudioPlayerTask() async {
  AudioServiceBackground.run(
    onStart: () {},
    onPlay: () {},
    onPause: () {},
    onStop: () {},
    onAddQueueItem: (String mediaId) {
      print("Queued: " + mediaId);
    },
    onClick: (MediaButton button) {},
  );
}