如何访问和显示播放列表，艺术家和所有音乐文件从sd卡

Question

我是Android开发的新手。我正在用mediaplayer实现一个简单的应用程序。我对如何从SD卡访问所有mp3文件有点困惑。我使用以下代码从SD卡下的歌曲文件夹中检索歌曲。

但在歌曲文件夹中，我还有一些子文件夹，里面有很多音频文件。我正在使用以下代码来检索歌曲。但它正在加载歌曲下的文件，而不是加载父文件夹（sdcard/songs）的其他子文件夹歌曲。如何从SDCard访问所有音频文件、播放列表和艺术家？

public class SongsManager {
// SDCard Path
final String MEDIA_PATH = new String("/sdcard/songs");
private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
// Constructor
public SongsManager(){
    
}
/**
 * Function to read all mp3 files from sdcard
 * and store the details in ArrayList
 * */
public ArrayList<HashMap<String, String>> getPlayList(){
    File home = new File(MEDIA_PATH);
 
    if (home.listFiles(new FileExtensionFilter()).length > 0) {
        for (File file : home.listFiles(new FileExtensionFilter())) {
            HashMap<String, String> song = new HashMap<String, String>();
            song.put("songTitle", file.getName().substring(0, (file.getName().length() - 4)));
            song.put("songPath", file.getPath());
            
            // Adding each song to SongList
            songsList.add(song);
        }
    }
    // return songs list array
    return songsList;
}
/**
 * Class to filter files which are having .mp3 extension
 * */
class FileExtensionFilter implements FilenameFilter {
    public boolean accept(File dir, String name) {
        return true;
    }
}
}

Answer 1

试试这个。

String[] STAR = { "*" };
int totalSongs;
public void ListAllSongs() 
    {
        Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
        if (MusicUtils.isSdPresent()) {
            cursor = managedQuery(allsongsuri, STAR, selection, null, null);
            totalSongs = cursor.getCount();
            if (cursor != null) {
                if (cursor.moveToFirst()) {
                    do {
                        String songname = cursor
                                .getString(cursor
                                        .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
                        int song_id = cursor.getInt(cursor
                                .getColumnIndex(MediaStore.Audio.Media._ID));
                        String fullpath = cursor.getString(cursor
                                .getColumnIndex(MediaStore.Audio.Media.DATA));
                        fullsongpath.add(fullpath);
                        String albumname = cursor.getString(cursor
                                .getColumnIndex(MediaStore.Audio.Media.ALBUM));
                        int album_id = cursor
                                .getInt(cursor
                                        .getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
                        String artistname = cursor.getString(cursor
                                .getColumnIndex(MediaStore.Audio.Media.ARTIST));
                        int artist_id = cursor
                                .getInt(cursor
                                        .getColumnIndex(MediaStore.Audio.Media.ARTIST_ID));
                                                } while (cursor.moveToNext());
                }
                cursor.close();
            }
        }
    }

Answer 2

你这样做似乎是可能的，但看起来不是"机器人"。有关ContentProviders和MediaStore的签出信息。音频

在那之后，我相信Chirag Raval代码会变得更加清晰，你将能够进一步研究它。

Answer 3

//declare your variables
private ArrayList<Song> songList;
//create a clas where you define your data
public class Song {
private long id;
private String title;
private String artist;
public Song(long songID, String songTitle, String songArtist) {
    id=songID;
    title=songTitle;
    artist=songArtist;
}
public long getID(){
    return id;
}
public String getTitle(){
    return title;
}
public String getArtist(){
    return artist;
}
}

    public void getSongLists(){
    ContentResolver musicResolver = context.getContentResolver();
    Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    String sel = MediaStore.Files.FileColumns.MIME_TYPE + "=?";
    String ext = MimeTypeMap.getSingleton().getMimeTypeFromExtension("mp3");
    String[] selExtARGS = new String[]{ext};
    Cursor musicCursor = musicResolver.query(musicUri, null, sel, selExtARGS, null);
    if(musicCursor!=null && musicCursor.moveToFirst()){
        //get columns
        int titleColumn = musicCursor.getColumnIndex(android.provider.MediaStore.Audio.Media.TITLE);
        int idColumn = musicCursor.getColumnIndex(android.provider.MediaStore.Audio.Media._ID);
        int artistColumn = musicCursor.getColumnIndex(android.provider.MediaStore.Audio.Media.ARTIST);
        int column_index = musicCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);
        //add songs to list
        do {
            long id = musicCursor.getLong(idColumn);
            String title = musicCursor.getString(titleColumn);
            String artist = musicCursor.getString(artistColumn);
            songList.add(new Song(id, title, artist));
        }
        while (musicCursor.moveToNext());
    }
   }