我正在构建一个具有标签布局的音乐播放器。其中一个标签是＆＃34; Genres＆＃34;（Genre.java），它显示RecyclerView中的歌曲类型（Android手机外部存储上的歌曲，通过查询）。我也为RecyclerView中的类型设置了onClickListeners。所以，当我点击其中一个类型时，它应该带我到另一个活动（GenresSongs.java），它显示属于该被点击类型的所有歌曲。
我的问题：
当我点击任何类型时，它会转到另一个活动，但会显示上次添加到数组中的歌曲。无论我点击哪种类型，都会把我带到同一首歌。
我想要的是什么：
当我点击列表中的一个类型时，它应该转到属于所点击类型的歌曲。我希望你明白我的观点。我将GenreID作为意图传递。
Genre.java（显示所有歌曲类型的课程）：
public class Genres extends Fragment {
private static final String TAG = "Genres";
RecyclerView recyclerView_genre;
GenresAdapter genresAdapter;
ArrayList<GenresModel> Genrelist = new ArrayList<>();
Cursor genrecursor;
long id;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.genres_activity, container, false);
recyclerView_genre = view.findViewById(R.id.recyclerView_genre);
LinearLayoutManager genreLayout = new LinearLayoutManager(getContext());
recyclerView_genre.setLayoutManager(genreLayout);
final Uri uri = MediaStore.Audio.Genres.EXTERNAL_CONTENT_URI;
genrecursor = getActivity().getContentResolver().query(uri,null,null, null, null);
if (genrecursor != null) {
if (genrecursor.moveToFirst()) {
do {
id = genrecursor.getLong(genrecursor.getColumnIndex(MediaStore.Audio.Genres._ID));
String name = genrecursor.getString(genrecursor.getColumnIndex(MediaStore.Audio.Genres.NAME));
GenresModel genresModel = new GenresModel(id,name);
Genrelist.add(genresModel);
Collections.sort(Genrelist, new Comparator<GenresModel>() {
@Override
public int compare(GenresModel lhs, GenresModel rhs) {
return lhs.getGenreName().compareTo(rhs.getGenreName());
}
});
} while (genrecursor.moveToNext());
}
genrecursor.close();
}
genresAdapter = new GenresAdapter(getContext(), Genrelist, new GenresAdapter.GenreItemClickListener() {
@Override
public void onClickListener(GenresModel genresModel, int GenrePosition) {
Intent nIntent = new Intent(getContext(), GenresSong.class);
nIntent.putExtra("genre_ID", id);
startActivity(nIntent);
}
});
recyclerView_genre.setAdapter(genresAdapter);
genresAdapter.notifyDataSetChanged();
return view;
}
GenresAdapter.java（Genres.java的适配器类）：
public class GenresAdapter extends RecyclerView.Adapter<GenresAdapter.GenresHolder> {
private Context gContext;
private ArrayList<GenresModel> GenreList = new ArrayList<>();
private GenreItemClickListener listenerGenre;
public GenresAdapter(Context gContext, ArrayList<GenresModel> genreList, GenresAdapter.GenreItemClickListener listenerGenre) {
this.gContext = gContext;
GenreList = genreList;
this.listenerGenre = listenerGenre;
}
@Override
public GenresAdapter.GenresHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view3 = LayoutInflater.from(gContext).inflate(R.layout.row_genre, parent, false);
return new GenresHolder(view3);
}
@Override
public void onBindViewHolder(GenresAdapter.GenresHolder holder, int position) {
final GenresModel genresModel1 = GenreList.get(position);
holder.genreText.setText( genresModel1.getGenreName());
holder.bindSong(genresModel1, listenerGenre);
}
@Override
public int getItemCount() {
return GenreList.size();
}
public class GenresHolder extends RecyclerView.ViewHolder {
TextView genreText;
public GenresHolder(View itemView) {
super(itemView);
genreText = itemView.findViewById(R.id.genreText);
}
public void bindSong(final GenresModel genresModel1, final GenreItemClickListener listenerGenre) {
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
listenerGenre.onClickListener(genresModel1, getLayoutPosition());
}
});
}
}
public interface GenreItemClickListener{
void onClickListener(GenresModel genresModel, int GenrePosition);
}
GenresSong.java（点击类型时应该显示歌曲的类）：
public class GenresSong extends Activity {
RecyclerView recyclerView_genreSong;
ArrayList <GenreSongModel> GenreSongList = new ArrayList<>();
GenresSongAdapter genresSongAdapter;
long genreID;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.genres_details);
recyclerView_genreSong = findViewById(R.id.recyclerView_genreSong);
LinearLayoutManager l1 = new LinearLayoutManager(getApplicationContext());
recyclerView_genreSong.setLayoutManager(l1);
genreID = getIntent().getExtras().getLong("genre_ID");
Uri uri = MediaStore.Audio.Genres.Members.getContentUri("external", genreID);
String[] projection ={MediaStore.Audio.Media.TITLE};
Cursor cursor = getApplicationContext().getContentResolver().query(uri, projection, null, null, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
String name = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE));
GenreSongModel s = new GenreSongModel(name);
GenreSongList.add(s);
} while (cursor.moveToNext());
}
cursor.close();
Collections.sort(GenreSongList, new Comparator<GenreSongModel>() {
@Override
public int compare(GenreSongModel lhs, GenreSongModel rhs) {
return lhs.getSongName().compareTo(rhs.getSongName());
}
});
}
genresSongAdapter = new GenresSongAdapter(getApplicationContext(), GenreSongList);
recyclerView_genreSong.setAdapter(genresSongAdapter);
genresSongAdapter.notifyDataSetChanged();
}
GenresSongAdapter.java（GenresSong.java的适配器类）：
public class GenresSongAdapter extends RecyclerView.Adapter<GenresSongAdapter.GenresSongHolder> {
Context gsContext;
ArrayList<GenreSongModel> GenresSongList2 = new ArrayList<>();
public GenresSongAdapter(Context gsContext, ArrayList<GenreSongModel> genresSongList2) {
this.gsContext = gsContext;
GenresSongList2 = genresSongList2;
}
@Override
public GenresSongAdapter.GenresSongHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v5 = LayoutInflater.from(gsContext).inflate(R.layout.row_genredetails, parent, false);
return new GenresSongHolder(v5);
}
@Override
public void onBindViewHolder(GenresSongAdapter.GenresSongHolder holder, int position) {
GenreSongModel genreSongModel = GenresSongList2.get(position);
holder.genreSongName.setText(genreSongModel.getSongName());
}
@Override
public int getItemCount() {
return GenresSongList2.size();
}
public class GenresSongHolder extends RecyclerView.ViewHolder {
TextView genreSongName;
public GenresSongHolder(View itemView) {
super(itemView);
genreSongName = itemView.findViewById(R.id.genreSongName);
}
}