Question

我想在我的音乐应用程序中显示流派但是当应用程序运行时，当我切换选项卡时，我的应用程序崩溃，应用程序停止工作并给出以下logcat error.i不知道该错误是什么。请帮助。

这是logcat

android.database.sqlite.SQLiteException：没有这样的列：_display_name （代码1）:,编译时：SELECT name，0，_display_name FROM audio_genres 在 android.database.DatabaseUtils.readExceptionFromParcel（DatabaseUtils.java:179）在 android.database.DatabaseUtils.readExceptionFromParcel（DatabaseUtils.java:135）在 android.content.ContentProviderProxy.query（ContentProviderNative.java:418）在android.content.ContentResolver.query（ContentResolver.java:754）在android.content.ContentResolver.query（ContentResolver.java:704）在android.content.ContentResolver.query（ContentResolver.java:662）在layout.BlankFragment3.getGenreList（BlankFragment3.java:97）在layout.BlankFragment3.onCreateView（BlankFragment3.java:77）在 android.support.v4.app.Fragment.performCreateView（Fragment.java:2192）在 android.support.v4.app.FragmentManagerImpl.moveToState（FragmentManager.java:1299）在 android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState（FragmentManager.java:1528）在 android.support.v4.app.FragmentManagerImpl.moveToState（FragmentManager.java:1595）在 android.support.v4.app.BackStackRecord.executeOps（BackStackRecord.java:758）在 android.support.v4.app.FragmentManagerImpl.executeOps（FragmentManager.java:2363）在 android.support.v4.app.FragmentManagerImpl.executeOpsTogether（FragmentManager.java:2149）在 android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps（FragmentManager.java:2103）在 android.support.v4.app.FragmentManagerImpl.execSingleAction（FragmentManager.java:1984）在 android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss（BackStackRecord.java:626）在 android.support.v4.app.FragmentPagerAdapter.finishUpdate（FragmentPagerAdapter.java:143）在android.support.v4.view.ViewPager.populate（ViewPager.java:1268）在 android.support.v4.view.ViewPager.setCurrentItemInternal（ViewPager.java:668）在 android.support.v4.view.ViewPager.setCurrentItemInternal（ViewPager.java:630）在 android.support.v4.view.ViewPager.setCurrentItem（ViewPager.java:611）在 android.support.design.widget.TabLayout $ ViewPagerOnTabSelectedListener.onTabSelected（TabLayout.java:2191）在 android.support.design.widget.TabLayout.dispatchTabSelected（TabLayout.java:1164）在 android.support.design.widget.TabLayout.selectTab（TabLayout.java:1157）在 android.support.design.widget.TabLayout.selectTab（TabLayout.java:1127）在 android.support.design.widget.TabLayout $ Tab.select（TabLayout.java:1426）在 android.support.design.widget.TabLayout $ TabView.performClick（TabLayout.java:1536）在android.view.View.onKeyUp（View.java:12222）在android.view.KeyEvent.dispatch（KeyEvent.java:2712）在android.view.View.dispatchKeyEvent（View.java:11465）

主要活动

public class BlankFragment3 extends Fragment {
    ArrayList<genreInfo> genreList = new ArrayList<>();
    RecyclerView recyclerView2;
    private genreAdapter genreAdapter1;
    long id;
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;


    public BlankFragment3() {
        // Required empty public constructor
    }


    // TODO: Rename and change types and number of parameters
    public static BlankFragment newInstance(String param1, String param2) {
        BlankFragment fragment = new BlankFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.genrere, container, false);
        recyclerView2 = rootView. findViewById(R.id.recyclerView2);
        genreAdapter1 = new genreAdapter(genreList, getActivity());
        recyclerView2.setAdapter(genreAdapter1);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
        DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView2.getContext(),
                linearLayoutManager.getOrientation());
        recyclerView2.setLayoutManager(linearLayoutManager);
        recyclerView2.addItemDecoration(dividerItemDecoration);
        getGenreList();
        return rootView;
    }


    public void getGenreList(){

final Uri uri = MediaStore.Audio.Genres.EXTERNAL_CONTENT_URI;

        String name=MediaStore.Audio.Genres.NAME;
        try {
            id = Long.parseLong(MediaStore.Audio.Genres._ID);
        }catch (Exception e)
        {
            e.printStackTrace();
        }
        String dName=MediaStore.Audio.Media.DISPLAY_NAME;
        //  final String tracks = MediaStore.Audio.Albums.NUMBER_OF_SONGS;

        final String[] columns = { name, String.valueOf(id), dName };
        Cursor cursor = getContext().getContentResolver().query(uri, columns, null, null, null);

        if(cursor!=null && cursor.moveToFirst()) do {

            id = cursor.getLong(cursor.getColumnIndex(String.valueOf(id)));
            name = cursor.getString(cursor.getColumnIndex(name));
            dName = cursor.getString(cursor.getColumnIndex(dName));
            //String artPath = cursor.getString(cursor.getColumnIndex(albumart));
            //Bitmap art = BitmapFactory.decodeFile(artPath);
            //    int nr = Integer.parseInt(cursor.getString(cursor.getColumnIndex(tracks)));
            genreInfo g = new genreInfo(id, name,dName);
            genreList.add(g);
        } while (cursor.moveToNext());
        if (cursor != null) {
            cursor.close();
        }
        recyclerView2.setAdapter(genreAdapter1);
    }


    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }

    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }



    public interface OnFragmentInteractionListener {
        void onFragmentInteraction(Uri uri);
    }
}

genreAdapter

public class genreAdapter extends RecyclerView.Adapter<genreAdapter.AlbumHolder> {
    ArrayList<genreInfo> genreList=new ArrayList<>();
    Context context;

    public genreAdapter(ArrayList<genreInfo> genreList, Context context) {
        this.genreList = genreList;
        this.context = context;
    }

    @Override
    public genreAdapter.AlbumHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View myView = LayoutInflater.from(context).inflate(R.layout.genre,parent,false);
        return new AlbumHolder(myView);
    }

    @Override
    public void onBindViewHolder(AlbumHolder holder, int position) {
        final genreInfo a = genreList.get(position);
        holder.album.setText(genreList.get(position).getName());
        holder.artist.setText(genreList.get(position).getdName());
     //   holder.album_art.setImageDrawable(Drawable.createFromPath(String.valueOf(albumList.get(position).getAlbumImg())));

    }
    @Override
    public int getItemCount() {
        return genreList.size();
    }

    public class AlbumHolder extends RecyclerView.ViewHolder {
        public TextView album;
        public TextView artist;
        //public ImageView album_art;
        public AlbumHolder(View itemView) {
            super(itemView);
           // album_art = (ImageView) itemView.findViewById(R.id.albumArt);
            artist = (TextView) itemView.findViewById(R.id.artistName);
            album = (TextView) itemView.findViewById(R.id.songName);
        }
    }
}

Answer 1

问题在于名为_display_name的列。检查此列的拼写。还要检查在创建audio_genres表时是否创建了此列。

类型未在我的应用中显示

1 个答案: