我已经阅读了官方文档,但我不明白这种方法的作用:
@Override
public void onLoadChildren(final String parentMediaId,
final Result<List<MediaItem>> result) {
...
// Assume for example that the music catalog is already loaded/cached.
List<MediaItem> mediaItems = new ArrayList<>();
// Check if this is the root menu:
if (MY_MEDIA_ROOT_ID.equals(parentMediaId)) {
// build the MediaItem objects for the top level,
// and put them in the mediaItems list
where is documented this part? how to build the media item?
} else {
// examine the passed parentMediaId to see which submenu we're at,
// and put the children of that menu in the mediaItems list
}
...
}
如果我想在电话里播放音乐,
如何根据手机的音乐“构建媒体项”?
最佳答案
我的答复有点晚了,但我希望这会有助于今后的怀疑。
在您的service.java中
case MEDIA_ID_ROOT:
for (MediaMetadataCompat track : mMusicProvider.getAllMusics()) {
String mediaId = track.getDescription().getMediaId();
//Artist song
String title = String.valueOf(track.getDescription().getTitle());
//Artist name
String subTitle = String.valueOf(track.getDescription().getSubtitle());
//Artist album
String descriptin = String.valueOf(track.getDescription().getDescription());
//Song duration
Long duration = track.getLong(MediaMetadataCompat.METADATA_KEY_DURATION);
Bundle songDuration = new Bundle();
songDuration.putLong(MediaMetadataCompat.METADATA_KEY_DURATION, duration);
MediaDescriptionCompat desc =
new MediaDescriptionCompat.Builder()
.setMediaId(mediaId)
.setTitle(title)
.setSubtitle(subTitle)
.setDescription(descriptin)
.setExtras(songDuration)
.build();
MediaBrowserCompat.MediaItem songList =
new MediaBrowserCompat.MediaItem(desc,
MediaBrowserCompat.MediaItem.FLAG_PLAYABLE);
mediaItems.add(songList);
}
break;
mmusicprovider是我模型的对象
在provider.java中
// Categorized caches for music track data:
private final LinkedHashMap<String, MediaMetadataCompat> mMusicListById;
public Iterable<MediaMetadataCompat> getAllMusics() {
if (mCurrentState != State.INITIALIZED || mMusicListById.isEmpty()) {
return Collections.emptyList();
}
return mMusicListById.values();
}
mediabrowsercompat.mediaitem基本上可以有mediaid、title、subtitle、description、iconbitmap、iconuri、bundle。在我的情况下,我需要这首歌的持续时间,所以我添加了一个额外的包。您可以添加更多的附加功能,如作曲家、年份、曲目编号等。
如果不需要任何额外信息,可以调用getDescription()。
for (MediaMetadataCompat track : mMusicProvider.getAllMusics()) {
MediaBrowserCompat.MediaItem bItem =
new MediaBrowserCompat.MediaItem(track.getDescription(),
MediaBrowserCompat.MediaItem.FLAG_PLAYABLE);
mediaItems.add(bItem);