我正在构建一个音乐播放器应用程序，并使用sd卡中的歌曲填充了recyclerView。我也设置了onClickListeners。所以当我点击一个项目（歌曲）时，该特定位置的歌曲开始播放。我想要的是当它完成播放时，我想让下一首歌像现代音乐播放器一样自动播放。我知道我必须使用OnCompletionListener，但我无法理解。
我是Android的新手。
Songs.java（这是一个片段）：
public class Songs extends Fragment {
public static final String Broadcast_PLAY_NEW_AUDIO = "com.musicplayer.musicana.PlayNewAudio";
public static final String TAG = "Songs";
RecyclerView recyclerView;
private ArrayList<SongInfoModel> SongList = new ArrayList<SongInfoModel>();
SongAdapter songAdapter;
ScaleInAnimationAdapter alphaAdapter;
MediaPlayer mediaPlayer;
MainActivity mainActivity;
private MediaPlayerService player;
boolean serviceBound = false;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.songs_activity, container, false);
// Activity activity = getActivity();
final MainActivity activity=(MainActivity)getActivity();
recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(linearLayoutManager);
songAdapter = new SongAdapter(getContext(), SongList, new SongAdapter.RecyclerItemClickListener() {
@Override
public void onClickListener(SongInfoModel song, int position) {
Toast.makeText(getContext(), song.getSongName(), Toast.LENGTH_SHORT).show();
Activity activity = getActivity();
if (activity instanceof MainActivity) {
mainActivity = (MainActivity) activity;
mainActivity.setsongText(song);
((MainActivity) activity).ButtonPause();
}
prepareSong(song);
}
@Override
public void onLongClickListener(SongInfoModel song, int position) {
Toast.makeText(getContext(), "You long clicked me, thank you!", Toast.LENGTH_SHORT).show();
}
});
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String selection = MediaStore.Audio.Media.IS_MUSIC + "!=0";
Cursor cursor = getActivity().getContentResolver().query(uri, null, selection, null, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
String name = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
Long duration = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION));
String data = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
Long albumId = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");
Uri albumArtUri = ContentUris.withAppendedId(sArtworkUri, albumId);
SongInfoModel s = new SongInfoModel(name, artist, null, null, null, duration, data,albumArtUri);
SongList.add(s);
} while (cursor.moveToNext());
}
cursor.close();
Collections.sort(SongList, new Comparator<SongInfoModel>() {
@Override
public int compare(SongInfoModel lhs, SongInfoModel rhs) {
return lhs.getSongName().compareTo(rhs.getSongName());
}
});
}
alphaAdapter = new ScaleInAnimationAdapter(songAdapter);
alphaAdapter.setDuration(1000);
alphaAdapter.setInterpolator(new OvershootInterpolator());
alphaAdapter.setFirstOnly(false);
recyclerView.setAdapter(alphaAdapter);
alphaAdapter.notifyDataSetChanged();
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
togglePlay(mp);
}
});
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mediaPlayer) {
}
});
activity.setOnSongClickListener(new MainActivity.OnSongCickListener() {
@Override
public void onsongClicked() {
if(mediaPlayer.isPlaying() && mediaPlayer!=null ){
mediaPlayer.pause();
activity.ButtonPlay();
} else {
mediaPlayer.start();
activity.ButtonPause();
}
}
});
return view;
}
private void prepareSong(SongInfoModel song) {
mediaPlayer.reset();
try {
mediaPlayer.setDataSource(song.getData());
mediaPlayer.prepareAsync();
} catch (IOException e) {
e.printStackTrace();
}
}
private void togglePlay(MediaPlayer mp) {
if (mp.isPlaying()) {
mp.stop();
mp.reset();
} else {
mp.start();
}
}
SongAdapter.java（recyclerVIews adapter）：
public class SongAdapter extends RecyclerView.Adapter<SongAdapter.SongHolder> {
ArrayList<SongInfoModel> SongList = new ArrayList<>();
Context context;
private RecyclerItemClickListener listener;
public SongAdapter(Context context, ArrayList<SongInfoModel> SongList, RecyclerItemClickListener listener) {
this.context = context;
this.SongList = SongList;
this.listener = listener;
}
@Override
public SongAdapter.SongHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.row_song, parent, false);
return new SongHolder(view);
}
@Override
public void onBindViewHolder(final SongAdapter.SongHolder holder, final int position) {
final SongInfoModel songInfoModel = SongList.get(position);
if(songInfoModel!= null){
holder.songName.setText(songInfoModel.SongName);
holder.artistName.setText(songInfoModel.ArtistName);
holder.duration.setText(String.valueOf(songInfoModel.duration));
String duration = Utility.convertDuration(songInfoModel.getDuration());
holder.duration.setText(duration);
Picasso.with(context).load(songInfoModel.getAlbumID()).placeholder(R.drawable.ic_launcher).into(holder.iv_artwork);
holder.bind(songInfoModel, listener);
}
}
@Override
public int getItemCount() {
return SongList.size();
}
public class SongHolder extends RecyclerView.ViewHolder {
TextView songName;
TextView artistName;
TextView duration;
private ImageView iv_artwork;
public SongHolder(View itemView) {
super(itemView);
songName = (TextView)itemView.findViewById(R.id.SongName);
artistName= (TextView)itemView.findViewById(R.id.ArtistName);
duration = (TextView) itemView.findViewById(R.id.duration);
iv_artwork = (ImageView) itemView.findViewById(R.id.iv_artwork);
}
public void bind(final SongInfoModel songInfoModel, final RecyclerItemClickListener listener) {
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
listener.onClickListener(songInfoModel, getLayoutPosition());
}
});
itemView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
listener.onLongClickListener(songInfoModel, getLayoutPosition());
return true;
}
});
}
}
public interface RecyclerItemClickListener{
void onClickListener(SongInfoModel song, int position);
void onLongClickListener(SongInfoModel song, int position);
}
}
答案 0 :(得分：2)
您可以像这样使用Media Player的完成侦听器
mediaPlayer.setOnCompletionListener（new OnCompletionListener（）{
public void onCompletion(MediaPlayer mp) {
//pass the path of the new song here
}
});
答案 1 :(得分：0)
我刚刚找到了解决方案！很容易！
在SongAdapter.java中：添加此内容，
private int selectedPosition;
public void setSelectedPosition(int selectedPosition) {
this.selectedPosition = selectedPosition;
}
public int getSelectedPosition() {
return selectedPosition;
}
在Songs.java中：添加此内容，
private void changeSelectedSong(int index){
songAdapter.notifyItemChanged(songAdapter.getSelectedPosition());
currentIndex = index;
songAdapter.setSelectedPosition(currentIndex);
songAdapter.notifyItemChanged(currentIndex);
}
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
if(currentIndex + 1 < SongList.size()){
SongInfoModel next = SongList.get(currentIndex + 1);
changeSelectedSong(currentIndex+1);
prepareSong(next);
mainActivity.setsongText(next);
}else{
SongInfoModel next = SongList.get(0);
changeSelectedSong(0);
prepareSong(next);
mainActivity.setsongText(next);
}
}
});
并在onClick中调用changeSelectedSong（position）。