Question

我正在尝试从播放列表中删除重复的歌曲。这是我用来从播放列表中删除歌曲的代码。

public static void removeFromPlaylist(final Context context, final long id,
            final long playlistId) {
        final Uri uri = MediaStore.Audio.Playlists.Members.getContentUri("external", playlistId);
        final ContentResolver resolver = context.getContentResolver();
        int del = resolver.delete(uri, Playlists.Members.AUDIO_ID + " = ? ", new String[] {
            Long.toString(id)
        });
        Log.e("DeleteFromPlaylist",""+del);
    }

但问题在于它会删除所有歌曲。假设我在播放列表Playlist1中添加了3次'SongOne'。当我删除'SongOne'时应该只删除一次，但这里所有3'SongOne'都被删除了。我在日志中得到'3'。那么我应该对代码进行哪些修改，使ContentResolver.delete()只删除一次？

谢谢！

Answer 1

您可以使用以下代码，这不是您需要测试的完整代码，因为我在这个区域没有任何IDE。

   final Uri uri = MediaStore.Audio.Playlists.Members.getContentUri("external", playlistId);
   final ContentResolver resolver = context.getContentResolver();
   Cursor cursor = resolver.query(uri,null , Playlists.Members.AUDIO_ID + " = ? ", new String[] {
        Long.toString(id)} , null , null ); 

 List<Long> ids = new ArrayList<Long>();
 if (cursor != null)
    while ( cursor.moveToNext())
    {
      ids.add ( cursor.getLong(cursor.getColumnIndex("id"))); // you need get id of song, this might be id

    }

for (int i = 1 ; i < ids.size() ; i++) // skip first index in list
     resolver.delete(uri, "id" + " = ? ", new String[] {
        Long.toString(ids.get(i)) });

Android：从播放列表中删除重复项

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