小编近期在搞一个音乐播放器App。练练手； 首先遇到一个问题。怎么获取本地的音乐文件？

    /**

     * 获取SD卡中的音乐文件

     *

     * @param context

     * @return

     */

    public static ArrayList<Music> getMusicFile(Context context) {

        //ArrayList<Music>存放音乐

        ArrayList<Music> MusicFiles = new ArrayList<>();

        //查询媒体数据库

        ContentResolver resolver = context.getContentResolver();

         /**

         * Uri：这个Uri代表要查询的数据库名称加上表的名称。

           这个Uri一般都直接从MediaStore里取得，比如我要取全部歌的信息，

          就必须利用MediaStore.Audio.Media. EXTERNAL _CONTENT_URI这个Uri。

*

         */

        Cursor cursor = resolver.query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,

                null, null, null, MediaStore.Audio.Media.DEFAULT_SORT_ORDER);

        //遍历媒体数据库

        if (cursor.moveToFirst()) {

            while (!cursor.isAfterLast()) {

                //歌曲编号MediaStore.Audio.Media._ID

                int id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media._ID));

                //歌曲标题

                String title = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));

                //歌曲的专辑名MediaStore.Audio.Media.ALBUM

                String album = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM));

                //歌曲的歌手名MediaStore.Audio.Media.ARTIST

                String artist = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));

                //歌曲文件的路径MediaStore.Audio.Media.DATA

                String url = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));

                //歌曲的总播放时长MediaStore.Audio.Media.DURATION

                int duration = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));

                //歌曲文件的大小MediaStore.Audio.Media.SIZE

                long size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE));

                if (size > 1024 * 800) {     //是否大于800K

                    if (title.equals("<unknown>") || title.equals("")) {

                        title = "未知";

                    }

                    if ("<unknown>".equals(artist) || "".equals(artist)) {

                        artist = "未知";

                    }

                    Music music = new Music(id, title, artist,

                            url, album, duration, size);

                    MusicFiles.add(music);

                }

                cursor.moveToNext();

            }

        }

        return MusicFiles;

    }

Music类：

public class Music  {

    private int id;

    private String name;

    private String singerName;

    private String url;

    private String album;

    private int totalTime;

    private long size;

    public Music(int id, String name, String singerName,

                 String url, String album, int totalTime, long size) {

        this.id = id;

        this.name = name;

        this.singerName = singerName;

        this.url = url;

        this.album = album;

        this.totalTime = totalTime;

        this.size = size;

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getSingerName() {

        return singerName;

    }

    public void setSingerName(String singerName) {

        this.singerName = singerName;

    }

    public String getUrl() {

        return url;

    }

    public void setUrl(String url) {

        this.url = url;

    }

    public String getAlbum() {

        return album;

    }

    public void setAlbum(String album) {

        this.album = album;

    }

    public int getTotalTime() {

        return totalTime;

    }

    public void setTotalTime(int totalTime) {

        this.totalTime = totalTime;

    }

    public long getSize() {

        return size;

    }

    public void setSize(long size) {

        this.size = size;

    }

}