权限配置暂时到此，后台播放问题并入生命周期管理同步开发

lib/services/audio_player_handler.dart

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+// lib/services/audio_player_handler.dart
+import 'package:audio_service/audio_service.dart';
+import 'playback_service.dart';
+import 'audio_service.dart' as local_audio;
+
+class AudioPlayerHandler extends BaseAudioHandler {
+  final PlaybackService _playback = PlaybackService();
+  late final local_audio.AudioService _localAudio;
+
+  MediaItem? _currentMediaItem;
+
+  AudioPlayerHandler() {
+    _localAudio = local_audio.AudioService();
+
+    // 1. 监听播放状态（只更新 playing）
+    _playback.player.stream.playing.listen((playing) {
+      playbackState.add(playbackState.value.copyWith(
+        playing: playing,
+      ));
+    });
+
+    // 2. ⭐ 进度更新：跳过，因为当前版本不支持 position 参数
+    //    通知栏进度条不会动，但播放/暂停/切歌功能正常
+    //    如果后续需要，可以升级 audio_service 版本或改用其他方案
+
+    // 3. 监听播放完成（触发下一首）
+    _playback.player.stream.completed.listen((_) {
+      _localAudio.next();
+    });
+
+    // 4. 监听时长变化，更新 MediaItem
+    _playback.player.stream.duration.listen((duration) {
+      if (_currentMediaItem != null) {
+        _currentMediaItem = _currentMediaItem!.copyWith(duration: duration);
+        mediaItem.add(_currentMediaItem);
+      }
+    });
+  }
+
+  /// 外部调用更新通知栏
+  void updateNotification({
+    required String id,
+    required String title,
+    required String artist,
+  }) {
+    _currentMediaItem = MediaItem(
+      id: id,
+      title: title,
+      artist: artist,
+      duration: _playback.player.state.duration,
+    );
+    mediaItem.add(_currentMediaItem);
+  }
+
+  // ---- AudioHandler 接口实现 ----
+  @override
+  Future<void> play() async {
+    _playback.resume();
+  }
+
+  @override
+  Future<void> pause() async {
+    _playback.pause();
+  }
+
+  @override
+  Future<void> stop() async {
+    _playback.stop();
+  }
+
+  @override
+  Future<void> seek(Duration position) async {
+    _playback.seek(position);
+  }
+
+  @override
+  Future<void> skipToNext() async {
+    _localAudio.next();
+  }
+
+  @override
+  Future<void> skipToPrevious() async {
+    _localAudio.previous();
+  }
+
+  @override
+  Future<void> click([MediaButton button = MediaButton.media]) async {
+    // 默认行为：打开 App
+  }
+}