如果您有歌曲ID，Android会从Media Store获取歌曲吗？

Question

I got a song id from a playlist in MediaStore, using

long id = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Playlists.Members.AUDIO_ID));

and the id is correct, but as the only other data available is CONTENT_DIRECTORY, DEFAULT_SORT_ORDER, PLAYLIST_ID, PLAY_ORDER, and _ID, I am not sure how to get the important parts of the song. I need the title, album, artist, etc., as if I was going through MediaStore.Audio.Media to get Song info.

I found an answer that I tried to modify to fit my needs, but I don't really understand querying or cursors, I am not sure how if there is a way to get a song.

If the only way to do this is to cycle through every single song until i find a matching ID i can do that, but it is wildly inefficient and there has to be a better way.

Thanks in advance!

Answer 1

I was able to query a song by ID using the following code:

    Uri mediaContentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    String[] projection = new String[] { MediaStore.Audio.Media._ID, MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.ALBUM,
            MediaStore.Audio.Media.DURATION, MediaStore.Audio.Media.DATA, MediaStore.Audio.Media.ALBUM_ID};
    String selection = MediaStore.Audio.Media._ID + "=?";
    String[] selectionArgs = new String[] {"" + id}; //This is the id you are looking for

    Cursor mediaCursor = getContentResolver().query(mediaContentUri, projection, selection, selectionArgs, null);

    if(mediaCursor.getCount() >= 0) {
        mediaCursor.moveToPosition(0);
        String title = mediaCursor.getString(mediaCursor.getColumnIndex(MediaStore.Audio.Media.TITLE));
        String album = mediaCursor.getString(mediaCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM));
        String artist = mediaCursor.getString(mediaCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
        long duration = mediaCursor.getLong(mediaCursor.getColumnIndex(MediaStore.Audio.Media.DURATION));

        //Do something with the data
    }

You can query for different things by changing the selection and selectionArgs. Here is the documentation from the query function:

  /* 
  Query the given URI, returning a {@link Cursor} over the result set.
  For best performance, the caller should follow these guidelines:
   - Provide an explicit projection, to prevent reading data from storage that aren't going to be used.
   - Use question mark parameter markers such as 'phone=?' instead of explicit values in the {@code selection} parameter, so that queries that differ only by those values will be recognized as the same for caching purposes.

   @param uri The URI, using the content:// scheme, for the content to retrieve.
   @param projection A list of which columns to return. Passing null will return all columns, which is inefficient.
   @param selection A filter declaring which rows to return, formatted as an SQL WHERE clause (excluding the WHERE itself). Passing null will return all rows for the given URI.
   @param selectionArgs You may include ?s in selection, which will be replaced by the values from selectionArgs, in the order that they appear in the selection. The values will be bound as Strings.
   @param sortOrder How to order the rows, formatted as an SQL ORDER BY clause (excluding the ORDER BY itself). Passing null will use the default sort order, which may be unordered.
   @return A Cursor object, which is positioned before the first entry, or null
   @see Cursor
 */

  public final Cursor query(Uri uri, String[] projection,
        String selection, String[] selectionArgs, String sortOrder)