列出所有音乐文件

//Some audio may be explicitly marked as not being music
String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";

String[] projection = {
	MediaStore.Audio.Media._ID,
	MediaStore.Audio.Media.ARTIST,
	MediaStore.Audio.Media.TITLE,
	MediaStore.Audio.Media.DATA,
	MediaStore.Audio.Media.DISPLAY_NAME,
	MediaStore.Audio.Media.DURATION
};

cursor = this.managedQuery(
	MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
	projection,
	selection,
	null,
	null);

private List<String> songs = new ArrayList<String>();
while(cursor.moveToNext()){
	songs.add(cursor.getString(0) + "||" + cursor.getString(1) + "||" +   cursor.getString(2) + "||" +   cursor.getString(3) + "||" +  cursor.getString(4) + "||" +  cursor.getString(5));
}