Ничего не показывает в Parsing JSON для Recycler View - PullRequest
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Ничего не показывает в Parsing JSON для Recycler View

1 голос
/ 29 апреля 2020

Я следую онлайн-руководству по созданию приложения Parsing JSON для Recycler View. Тем не менее, он ничего не показывает в приложении. Я не знаю, что с этим случилось. Может кто-нибудь помочь мне разобраться в проблеме? Спасибо. введите описание изображения здесь

MainActivity. java

public class MainActivity extends AppCompatActivity {
    RecyclerView recyclerView;
    List<net.smallacademy.songslist.Song> songs;
    private static String JSON_URL = "http://starlord.hackerearth.com/studio";
    Adapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = findViewById(R.id.songsList);
        songs = new ArrayList<>();
        extractSongs();

    }

    private void extractSongs() {
        RequestQueue queue = Volley.newRequestQueue(this);
        JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, JSON_URL, null, new Response.Listener<JSONArray>() {
            @Override
            public void onResponse(JSONArray response) {
                for (int i = 0; i < response.length(); i++) {
                    try {
                        JSONObject songObject = response.getJSONObject(i);

                        net.smallacademy.songslist.Song song = new net.smallacademy.songslist.Song();
                        song.setTitle(songObject.getString("song").toString());
                        song.setArtists(songObject.getString("artists".toString()));
                        song.setCoverImage(songObject.getString("cover_image"));
                        song.setSongURL(songObject.getString("url"));
                        songs.add(song);

                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }

                recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
                adapter = new Adapter(getApplicationContext(),songs);
                recyclerView.setAdapter(adapter);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.d("tag", "onErrorResponse: " + error.getMessage());
            }
        });

        queue.add(jsonArrayRequest);
    }
}

Song. java

public class Song {
    private String title;
    private String artists;
    private String coverImage;
    private String songURL;

    public  Song(){}
    public Song(String title,String artists,String coverImage,String songURL){
        this.title = title;
        this.artists = artists;
        this.coverImage = coverImage;
        this.songURL = songURL;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getArtists() {
        return artists;
    }

    public void setArtists(String artists) {
        this.artists = artists;
    }

    public String getCoverImage() {
        return coverImage;
    }

    public void setCoverImage(String coverImage) {
        this.coverImage = coverImage;
    }

    public String getSongURL() {
        return songURL;
    }

    public void setSongURL(String songURL) {
        this.songURL = songURL;
    }
}

Адаптер. java


public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
    LayoutInflater inflater;
    List<net.smallacademy.songslist.Song> songs;

    public Adapter(Context ctx, List<net.smallacademy.songslist.Song> songs) {
        this.inflater = LayoutInflater.from(ctx);
        this.songs = songs;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.custom_list_layout,parent,false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.songTitle.setText(songs.get(position).getTitle());
        holder.songArtists.setText(songs.get(position).getArtists());
        Picasso.get().load(songs.get(position).getCoverImage()).into(holder.songCoverImage);

    }

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

    public class ViewHolder extends RecyclerView.ViewHolder{
        TextView songTitle, songArtists;
        ImageView songCoverImage;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            songTitle = itemView.findViewById(R.id.songTitle);
            songArtists = itemView.findViewById(R.id.songArtist);
            songCoverImage = itemView.findViewById(R.id.coverImage);

        }
    }
}

Activity_main. xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/songsList"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

custom_list_layout. xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <ImageView
                android:id="@+id/coverImage"
                android:layout_width="75dp"
                android:layout_height="75dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.0"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@drawable/ic_launcher_background"
                tools:ignore="VectorDrawableCompat" />

            <TextView
                android:id="@+id/songTitle"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="16dp"
                android:layout_marginTop="8dp"
                android:text="Song Title"
                android:textSize="18sp"
                android:textStyle="bold"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.0"
                app:layout_constraintStart_toEndOf="@+id/coverImage"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.0"
                android:layout_marginLeft="16dp" />

            <TextView
                android:id="@+id/songArtist"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="16dp"
                android:text="Song Artist"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.0"
                app:layout_constraintStart_toEndOf="@+id/coverImage"
                app:layout_constraintTop_toBottomOf="@+id/songTitle"
                android:layout_marginLeft="16dp" />
        </androidx.constraintlayout.widget.ConstraintLayout>
    </androidx.cardview.widget.CardView>

</androidx.constraintlayout.widget.ConstraintLayout>

1 Ответ

0 голосов
/ 29 апреля 2020

Пожалуйста, перенесите этот код ниже в метод onCreate 

recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));

, а затем измените оба тега Recyclerview 

 android:layout_width="match_parent"
 android:layout_height="wrap_content"
...