在android中列出相册

Question

我正在android中开发一个简单的音频播放器。我想在设备中列出相册。

我试过这个代码

String where = new String();
where = MediaStore.Audio.Media.IS_MUSIC + "=1";
private Cursor managedCursor;
managedCursor = managedQuery(
        MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
        new String[] {  
            MediaStore.Audio.Media.TITLE,
            MediaStore.Audio.Media._ID,
            MediaStore.Audio.Media.ALBUM,       
            MediaStore.Audio.Media.ALBUM_ID,    
            MediaStore.Audio.Media.ARTIST,
            MediaStore.Audio.Media.ARTIST_ID
        },
        where,                                  
        null,                                       
        MediaStore.Audio.Media.DEFAULT_SORT_ORDER   
    );
  ListAdapter adapter = new AlbumListAdapter(
        this,                                   
        R.layout.albumlist_item,                
        managedCursor,                          
        new String[] {                          
            MediaStore.Audio.Media.ALBUM,       
            MediaStore.Audio.Media.ARTIST           
        },
        new int[] {                             
            R.id.text_album, 
            R.id.text_artist 
        }
    );
    setListAdapter(adapter);

但这个代码列出了设备中的所有歌曲。

Android媒体商店DB的结构是什么。

任何人都请帮忙。

Answer 1

您应该像这个一样查询相册

String[] projection = new String[] { Albums._ID, Albums.ALBUM, Albums.ARTIST, Albums.ALBUM_ART, Albums.NUMBER_OF_SONGS };
String selection = null;
String[] selectionArgs = null;
String sortOrder = Media.ALBUM + " ASC";
Cursor cursor = contentResolver.query(Albums.EXTERNAL_CONTENT_URI, projection, selection, selectionArgs, sortOrder);

http://developer.android.com/reference/android/provider/MediaStore.Audio.Albums.html

艺术家、播放列表和流派都可以使用正确的EXTERNAL_CONTENT_URI和相应的投影以类似的方式进行查询。

希望能有所帮助。。。

Answer 2

使用此简化代码获取相册列表

public ArrayList<AlbumModel> getListOfAlbums(Context context) {
            String where = null;
            final Uri uri = MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI;
            final String _id = MediaStore.Audio.Albums._ID;
            final String album_name = MediaStore.Audio.Albums.ALBUM;
            final String artist = MediaStore.Audio.Albums.ARTIST;
            final String albumart = MediaStore.Audio.Albums.ALBUM_ART;
            final String tracks = MediaStore.Audio.Albums.NUMBER_OF_SONGS;
            final String[] columns = { _id, album_name, artist, albumart, tracks };
            Cursor cursor = context.getContentResolver().query(uri, columns, where,
                    null, null);
            ArrayList<AlbumModel> list = new ArrayList<AlbumModel>();
            // add playlsit to list
            if (cursor.moveToFirst()) {
                do {
                    AlbumModel albumData = new AlbumModel();
                    albumData
                            .setAlbumID(cursor.getLong(cursor.getColumnIndex(_id)));
                    albumData.setAlbumName(cursor.getString(cursor
                            .getColumnIndex(album_name)));
                    albumData.setALbumArtist(cursor.getString(cursor
                            .getColumnIndex(artist)));
                    albumData.setAlbumArt(cursor.getString(cursor
                            .getColumnIndex(albumart)));
                    albumData.setTracks(cursor.getString(cursor
                            .getColumnIndex(tracks)));
                    list.add(albumData);
                } while (cursor.moveToNext());
            }
            cursor.close();
            return list;
        }

Answer 3

public class Album {
private long id;
private String albumName;
private String artistName;
private int nr_of_songs;
private Bitmap albumImg;
public Album(long id, String albumName, String artistName, Bitmap albumImg,  int nr_of_songs) {
    this.albumImg = albumImg;
    this.id = id;
    this.albumName = albumName;
    this.artistName = artistName;
    this.nr_of_songs = nr_of_songs;
}
public void setId(long id) {
    this.id = id;
}
public void setAlbumName(String albumName) {
    this.albumName = albumName;
}
public void setArtistName(String artistName) {
    this.artistName = artistName;
}
public void setAlbumImg(Bitmap albumImg) {
    this.albumImg = albumImg;
}
public void setNr_of_songs(int nr_of_songs) {
    this.nr_of_songs = nr_of_songs;
}
public long getID(){
    return id;
}
public String getAlbumName(){
    return albumName;
}
public String getArtistName() {
    return artistName;
}
public Bitmap getAlbumImg() {
    return albumImg;
}
public int getNr_of_songs() {
    return nr_of_songs;
}
}

 public void getAlbumsLists(){
    String where = null;
    final Uri uri = MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI;
    final String _id = MediaStore.Audio.Albums._ID;
    final String album_name = MediaStore.Audio.Albums.ALBUM;
    final String artist = MediaStore.Audio.Albums.ARTIST;
    final String albumart = MediaStore.Audio.Albums.ALBUM_ART;
    final String tracks = MediaStore.Audio.Albums.NUMBER_OF_SONGS;
    final String[] columns = { _id, album_name, artist, albumart, tracks };
    Cursor cursor = context.getContentResolver().query(uri, columns, where, null, null);
    if(cursor!=null && cursor.moveToFirst()){
        do {
            long id = cursor.getLong(cursor.getColumnIndex(_id));
            String name = cursor.getString(cursor.getColumnIndex(album_name));
            String artist2 = cursor.getString(cursor.getColumnIndex(artist));
            String artPath = cursor.getString(cursor.getColumnIndex(albumart));
            Bitmap art = BitmapFactory.decodeFile(artPath);
            int nr =Integer.parseInt(cursor.getString(cursor.getColumnIndex(tracks)));
            albumList.add(new Album(id, name, artist2, art, nr));
        } while (cursor.moveToNext());
    }
    cursor.close();
}

Answer 4

这是的原始答案

我通过检查它们是否已经添加到我的地图中来对这些独特的相册进行排序

public Map<String, String> getAlbumList(Context c) {
    //setup map and cursor
    Map<String, String> result = new HashMap<String, String>();
    String selection = MediaStore.Audio.Media.IS_MUSIC + " !=0";
    final Cursor mCursor = c.getContentResolver().query(
            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
            new String[] {MediaStore.Audio.Media.ALBUM,
                    MediaStore.Audio.Media.ARTIST,
                    MediaStore.Audio.Media.ALBUM_ID,}, selection, null,
                   "LOWER ("+MediaStore.Audio.Media.ALBUM + ") ASC");
    int count = mCursor.getCount();

    String[] mArtist = new String[count];
    String[] mAlbum = new String[count];
    String[] AlbumID = new String[count];
    int i = 0;
    int j = 0;
    if (mCursor.moveToFirst()) {
        do {
            mAlbum[i] = mCursor
                    .getString(mCursor
                            .getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM));
            mArtist[i] = mCursor.getString(mCursor
                    .getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
            AlbumID[i] = Long.toString(mCursor
                    .getLong(mCursor
                            .getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM_ID)));
                                    //checking for same previous value
            if(result.containsValue(mAlbum[i])){
            }else{
            result.put("artist" + j, mArtist[i]);
            result.put("album" + j, mAlbum[i]);
            result.put("AlbumID" + j, AlbumID[i]);
            j = j + 1;
            }
            i = i + 1;
        } while (mCursor.moveToNext());
    }
    result.put("count", Integer.toString(j));
    mCursor.close();
    return result;
}
}

也许不是专辑独特排序的最漂亮的解决方案。。。但它完全按照预期工作，而不会在sqlite上摸索。。。。

我在这里传递了一个上下文，因为我在一个带有自定义适配器的片段中使用列表视图，而没有活动上下文getContentResolver（）不起作用。。。。

原始答案的加数

mArt、mData、mAlbums和mArtists是阵列列表。。。

private void getList(View view){
    mArt.clear();
    mAlbums.clear();
    mArtists.clear();
    String[] projection = {"DISTINCT " + MediaStore.Audio.Media.ALBUM_ID,
            MediaStore.Audio.Media.ALBUM,
            MediaStore.Audio.Media.ARTIST
    } ;
    String[] projection2 = {"Distinct " + MediaStore.Audio.Albums.ALBUM,
    MediaStore.Audio.Albums.NUMBER_OF_SONGS};
    Cursor mCursor =  getActivity().getApplicationContext().getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, projection, "0==0 ) GROUP BY (" + MediaStore.Audio.Media.ALBUM_ID, null, MediaStore.Audio.Media.ALBUM + " COLLATE NOCASE ASC");
    Cursor mCursor2 = getActivity().getApplicationContext().getContentResolver().query(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI, projection2, null, null, MediaStore.Audio.Albums.ALBUM + " COLLATE NOCASE ASC");
    if(mCursor != null && mCursor.getCount() > 0 && mCursor2 != null && mCursor2.getCount() > 0){
        CursorJoiner joiner = new CursorJoiner(mCursor, new String[]{MediaStore.Audio.Media.ALBUM},mCursor2, new String[]{MediaStore.Audio.Albums.ALBUM});
        for (CursorJoiner.Result joinerResult : joiner) {
            switch (joinerResult) {
                case LEFT:
                    break;
                case RIGHT:
                    break;
                case BOTH:
                    String songs_s = "Song";
                    int tracks = mCursor2.getInt(mCursor2.getColumnIndex(MediaStore.Audio.Albums.NUMBER_OF_SONGS));
                    if (tracks > 1) {
                        songs_s = "Songs";
                    }
                    mArtists.add(tracks + " " + songs_s + " By " + mCursor.getString(mCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST)));
                    mAlbums.add(mCursor2.getString(mCursor2.getColumnIndex(MediaStore.Audio.Albums.ALBUM)));
                    mArt.add(ContentUris.withAppendedId(Uri.parse("content://media/external/audio/albumart"), mCursor.getInt(mCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID))));
            }
        }
    }
    mCursor.close();
    mCursor2.close();
}

选择中的GROUP BY子句保证了专辑的唯一性，因为专辑的艺术是由专辑id引起的，这一行：

mArt.add(ContentUris.withAppendedId(Uri.parse("content://media/external/audio/albumart"), mCursor.getInt(mCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID))));

确保相册艺术和相册处于同一位置。。。

我在这里使用了一个光标连接程序，这样我就可以获得艺术家、专辑和专辑中的歌曲数量。。。这只能从两个单独的查询中返回。。。