目前状态栏控制大部分已生效，剩余暂停到播放的链路还有问题

lib/services/audio_player_handler.dart

@@ -1,4 +1,4 @@
-// lib/services/audio_player_handler.dart
+import 'package:flutter/material.dart';
 import 'package:audio_service/audio_service.dart';
 import 'playback_service.dart';
 import 'audio_service.dart' as local_audio;
@@ -7,84 +7,155 @@ 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,
-      ));
+      _updatePlaybackState(playing: playing);
+      _syncMediaItem();
     });
 
-    // 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((_) {
+      debugPrint('🎵 [handler] playback completed, auto next');
       _localAudio.next();
+      _updatePlaybackState();
+      _syncMediaItem();
     });
 
-    // 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);
+      final current = mediaItem.value;
+      if (current != null && current.duration != duration) {
+        mediaItem.add(current.copyWith(duration: duration));
       }
     });
   }
 
-  /// 外部调用更新通知栏
+  void _syncMediaItem() {
+    final song = _localAudio.currentSong;
+    debugPrint(
+        '🎵 [handler] _syncMediaItem: currentSong = ${song?.title ?? "null"}');
+    if (song != null) {
+      mediaItem.add(MediaItem(
+        id: song.id,
+        title: song.title,
+        artist: song.artist,
+        duration: _playback.player.state.duration,
+      ));
+    }
+  }
+
   void updateNotification({
     required String id,
     required String title,
     required String artist,
   }) {
-    _currentMediaItem = MediaItem(
+    mediaItem.add(MediaItem(
       id: id,
       title: title,
       artist: artist,
       duration: _playback.player.state.duration,
-    );
-    mediaItem.add(_currentMediaItem);
+    ));
+    _updatePlaybackState();
+  }
+
+  void _updatePlaybackState({bool? playing}) {
+    final isPlaying = playing ?? _playback.player.state.playing;
+    debugPrint('🎵 _updatePlaybackState: isPlaying=$isPlaying');
+
+    final controls = [
+      MediaControl.skipToPrevious,
+      if (isPlaying) MediaControl.pause else MediaControl.play,
+      MediaControl.skipToNext,
+    ];
+
+    debugPrint('🎵 controls: ${controls.map((c) => c.action).join(', ')}');
+
+    playbackState.add(PlaybackState(
+      controls: controls,
+      processingState: AudioProcessingState.ready,
+      playing: isPlaying,
+      androidCompactActionIndices: const [0, 1, 2],
+      updateTime: DateTime.now(),
+    ));
   }
 
-  // ---- AudioHandler 接口实现 ----
   @override
   Future<void> play() async {
+    debugPrint('🎵 [audio_service] play() called');
     _playback.resume();
+    _updatePlaybackState(playing: true);
+    _syncMediaItem();
   }
 
   @override
   Future<void> pause() async {
+    debugPrint('🎵 [audio_service] pause() called');
     _playback.pause();
+    _updatePlaybackState(playing: false);
   }
 
   @override
   Future<void> stop() async {
+    debugPrint('🎵 [audio_service] stop() called');
     _playback.stop();
+    _updatePlaybackState(playing: false);
   }
 
   @override
   Future<void> seek(Duration position) async {
+    debugPrint('🎵 [audio_service] seek() called: $position');
     _playback.seek(position);
   }
 
   @override
   Future<void> skipToNext() async {
+    debugPrint('🎵 [audio_service] skipToNext() called');
     _localAudio.next();
+    _updatePlaybackState();
+    _syncMediaItem();
   }
 
   @override
   Future<void> skipToPrevious() async {
+    debugPrint('🎵 [audio_service] skipToPrevious() called');
     _localAudio.previous();
+    _updatePlaybackState();
+    _syncMediaItem();
   }
 
   @override
   Future<void> click([MediaButton button = MediaButton.media]) async {
-    // 默认行为：打开 App
+    debugPrint(
+        '🎵 [audio_service] click(): ${button.name} (index: ${button.index})');
+
+    final name = button.name.toLowerCase();
+
+    if (name.contains('play') || name.contains('media')) {
+      debugPrint('🎵 → play() via click');
+      await play();
+      return;
+    }
+    if (name.contains('pause')) {
+      debugPrint('🎵 → pause() via click');
+      await pause();
+      return;
+    }
+    if (name.contains('next') || name.contains('skip_next')) {
+      debugPrint('🎵 → skipToNext() via click');
+      await skipToNext();
+      return;
+    }
+    if (name.contains('previous') || name.contains('skip_previous')) {
+      debugPrint('🎵 → skipToPrevious() via click');
+      await skipToPrevious();
+      return;
+    }
+
+    debugPrint('🎵 → fallback toggle');
+    if (_playback.player.state.playing) {
+      await pause();
+    } else {
+      await play();
+    }
   }
 }