java - RecyclerView 不显示数据 1 正在工作，但其他没有显示任何内容，有什么想法吗？

Question

构建电影应用程序，迷失在为什么当另一个以相同方式实现并工作时此回收器 View 不会显示任何内容的逻辑中。

确实有一个错误，就是找不到它。一直看着屏幕很长时间。提前致谢!!

XML:

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:background="@color/colorPrimaryDark"
    tools:context="com.example.mrmohammad.movies4u.DetailActivity"

    >

    <LinearLayout
        android:id="@+id/ad"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="10dp">

        <ScrollView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            tools:showIn="@layout/activity_detail">

            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"

                >


                <TextView
                    android:id="@+id/tv_title_movie"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="16dp"
                    android:layout_marginStart="16dp"
                    android:layout_marginTop="@dimen/tv_title_movie_margin_top_content_detail"
                    android:background="@drawable/bg_rating"
                    android:padding="@dimen/tv_title_movie_padding_content_detail"
                    android:text="Harry Potter"
                    android:textColor="#fff"
                    android:textSize="21sp"
                    android:textStyle="bold"
                    app:layout_constraintLeft_creator="1"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_creator="1"
                    app:layout_constraintTop_toTopOf="parent" />

                <TextView
                    android:id="@+id/tv_release_year"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="16dp"
                    android:layout_marginStart="16dp"
                    android:layout_marginTop="@dimen/tv_release_year_content_detail_rating"
                    android:background="@drawable/bg_rating"
                    android:padding="@dimen/tv_title_movie_padding_content_detail"
                    android:text="2018"
                    android:textColor="#fff"
                    android:textSize="16sp"
                    app:layout_constraintLeft_creator="1"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_creator="1"
                    app:layout_constraintTop_toBottomOf="@id/tv_title_movie" />


                <TextView
                    android:id="@+id/tv_rating"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="16dp"
                    android:layout_marginStart="16dp"
                    android:layout_marginTop="@dimen/tv_release_year_content_detail_rating"
                    android:background="@drawable/bg_rating"
                    android:drawableLeft="@drawable/ic_star_black_24dp"
                    android:padding="@dimen/tv_title_movie_padding_content_detail"
                    android:paddingRight="5dp"
                    android:text="8.9"
                    android:textColor="#fff"
                    android:textSize="16sp"
                    android:textStyle="bold"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/tv_release_year" />


                <RelativeLayout
                    android:id="@+id/llsynopsisbtn"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="16dp"
                    android:layout_marginStart="16dp"
                    android:layout_marginTop="@dimen/tv_release_year_content_detail_rating"
                    android:orientation="horizontal"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/tv_rating">


                    <TextView
                        android:id="@+id/tv_synopsis_label"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:background="@drawable/bg_rating"
                        android:padding="@dimen/tv_title_movie_padding_content_detail"

                        android:text="@string/synopsis"
                        android:textColor="#fff"
                        android:textSize="18sp" />

                    <View
                        android:id="@+id/emptyView"
                        android:layout_width="0dp"
                        android:layout_height="0dp"
                        android:layout_toRightOf="@id/tv_synopsis_label"
                        android:layout_weight="1" />


                    <LinearLayout
                        android:layout_width="match_parent"
                        android:layout_height="40dp"
                        android:gravity="end"
                        android:orientation="horizontal">


                        <ImageView
                            android:id="@+id/share"
                            android:layout_width="35dp"
                            android:layout_height="35dp"
                            android:contentDescription="Share..."
                            android:padding="4dp"
                            android:src="@drawable/ic_share_black_24dp" />

                        <ImageView
                            android:id="@+id/saveFav"
                            android:layout_width="35dp"
                            android:layout_height="35dp"
                            android:layout_below="@id/share"
                            android:contentDescription="Save in Favorites"
                            android:padding="4dp"
                            android:src="@drawable/thumbsup" />

                        <ImageView
                            android:id="@+id/deleteFav"
                            android:layout_width="35dp"
                            android:layout_height="35dp"

                            android:layout_toRightOf="@id/saveFav"
                            android:contentDescription="Delete from Favorites"
                            android:padding="4dp"
                            android:src="@drawable/delete" />


                    </LinearLayout>


                </RelativeLayout>

                <TextView
                    android:id="@+id/tv_synopsis"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="@dimen/synopsis_margin_left"
                    android:layout_marginRight="@dimen/synopsis_margin_right"
                    android:layout_marginTop="@dimen/synopsis_margin_top"

                    android:text="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitationlaboris nisi ut aliquip ex ea commodo consequat."
                    android:textColor="#fff"
                    android:textSize="15sp"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/llsynopsisbtn" />

                <TextView
                    android:id="@+id/thumbnailURL"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:visibility="invisible" />

                <LinearLayout
                    android:id="@+id/linLayContentDetail"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="16dp"
                    android:layout_marginStart="16dp"
                    android:layout_marginTop="4dp"
                    android:orientation="vertical"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/tv_synopsis">

                    <TextView
                        android:id="@+id/trailer"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="8dp"
                        android:background="@drawable/bg_rating"
                        android:padding="8dp"
                        android:text="Trailers"
                        android:textColor="#fff"
                        android:textSize="20sp"


                        />

                    <android.support.v7.widget.RecyclerView
                        android:id="@+id/rvTrailers"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_margin="3dp"
                        android:clipToPadding="false"
                        android:padding="12dp"
                        android:paddingBottom="25dp"
                        android:scrollbars="vertical"

                        >


                    </android.support.v7.widget.RecyclerView>

                </LinearLayout>


                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="16dp"
                    android:layout_marginStart="16dp"
                    android:layout_marginTop="4dp"
                    android:orientation="vertical"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/linLayContentDetail">

                    <TextView
                        android:id="@+id/review"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="8dp"
                        android:background="@drawable/bg_rating"
                        android:padding="8dp"
                        android:text="Reviews"
                        android:textColor="#fff"
                        android:textSize="20sp"


                        />

                    <android.support.v7.widget.RecyclerView
                        android:id="@+id/rvReview"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_margin="3dp"
                        android:clipToPadding="false"
                        android:padding="12dp"
                        android:paddingBottom="25dp"


                        >

                        <!--HERE IS TEH RECYCLERVIEW THAT DONT DISPLAY-->




                    </android.support.v7.widget.RecyclerView>

                </LinearLayout>


            </android.support.constraint.ConstraintLayout>

        </ScrollView>

    </LinearLayout>

</RelativeLayout>

详细 Activity :

    public class DetailActivity extends AppCompatActivity {

    TextView movieName, releaseDate, userRating, synopsis;
    int id;
    ImageView iv, share, saveFav, deletFav;
    private RecyclerView rvDetail, rvReview;
    private TrailerAdapter adapter;
    private ReviewAdapter reviewAdapter;
    private List<Trailer> trailerList;
    private List<Review> reviewList;
    public static final String BASE_URL = 
    "https://image.tmdb.org/t/p/w500";


    public static final String TAG = DetailActivity.class.getSimpleName();
    public MovieDbHelper dbHelper;
    private Movie favoriteMovie;
    private AppCompatActivity activity = DetailActivity.this;
    String poster, overview, rating, movieTitle, release;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail);
        Stetho.initializeWithDefaults(this);


        share = findViewById(R.id.share);
        saveFav = findViewById(R.id.saveFav);
        deletFav = findViewById(R.id.deleteFav);


        final int movie_id = getIntent().getExtras().getInt("id");

        if (checkFavoriteMovie(movie_id)) {

            //Is a favorite
            saveFav.setVisibility(View.GONE);
            saveFav.setEnabled(false);

            deletFav.setEnabled(true);
            deletFav.setVisibility(View.VISIBLE);


        } else {
            deletFav.setVisibility(View.GONE);
            deletFav.setEnabled(false);
            saveFav.setEnabled(true);
            saveFav.setVisibility(View.VISIBLE);
        }


        iv = findViewById(R.id.iv_detail);
        movieName = findViewById(R.id.tv_title_movie);
        releaseDate = findViewById(R.id.tv_release_year);
        userRating = findViewById(R.id.tv_rating);
        synopsis = findViewById(R.id.tv_synopsis);

        Intent intentFromAdapter = getIntent();
        if (intentFromAdapter.hasExtra("original_title")) {
            poster = 
        intentFromAdapter.getExtras().getString("poster_path");
            movieTitle = 
        intentFromAdapter.getExtras().getString("original_title");
            overview = intentFromAdapter.getExtras().getString("overview");
            rating = 
        intentFromAdapter.getExtras().getString("vote_average");
            release = 
        intentFromAdapter.getExtras().getString("release_date");

            Picasso.with(this).load(BASE_URL + poster).into(iv);
            movieName.setText(movieTitle);
            releaseDate.setText(release);
            userRating.setText(rating);
            synopsis.setText(overview);

        } else {
            Toast.makeText(this, "No Data...", Toast.LENGTH_SHORT).show();
        }

        SharedPreferences sharedPreferences = 
        PreferenceManager.getDefaultSharedPreferences(this);


        saveFav.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if (checkFavoriteMovie(movie_id)) {


                    Toast.makeText(activity, "Already added!", 
                Toast.LENGTH_SHORT).show();

                } else {


                    SharedPreferences.Editor editor = 

getSharedPreferences("com.example.mrmohammad.movies4u.DetailActivity", MODE_PRIVATE).edit();
                    editor.putBoolean("Favorite Added", true);
                    editor.commit();
                    addFavorites();
                    Toast.makeText(DetailActivity.this, "Movie Added successfully...", Toast.LENGTH_SHORT).show();

                }
//

                saveFav.setEnabled(false);
                deletFav.setEnabled(true);
                deletFav.setVisibility(View.VISIBLE);
                saveFav.setVisibility(View.GONE);
//


            }
        });

        deletFav.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                SharedPreferences.Editor editor = getSharedPreferences("com.example.mrmohammad.movies4u.DetailActivity", MODE_PRIVATE).edit();
                editor.putBoolean("Favorite Removed", true);
                editor.commit();

                removeFromFavorites(movie_id);
                Toast.makeText(DetailActivity.this, "Movie Removed...", Toast.LENGTH_SHORT).show();


//


                deletFav.setEnabled(false);
                saveFav.setEnabled(true);
                deletFav.setVisibility(View.GONE);
                saveFav.setVisibility(View.VISIBLE);


//
            }

        });

        share.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String d = movieName.getText().toString().trim();
                String s = "http://www.youtube.com/watch?v=" + d;
                s = s.replaceAll(" ", "%20");
                String full = "CLICK LINK " + s;

                Intent shareIntent = ShareCompat.IntentBuilder.from(DetailActivity.this)
                        .setType("text/plain")
                        .setText(full)
                        .getIntent();
                startActivity(shareIntent);
            }
        });


        initializeViews();


    }


    private void initializeViews() {

        /////// Trailers

        trailerList = new ArrayList<>();
        adapter = new TrailerAdapter(this, trailerList);
        RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
        rvDetail = findViewById(R.id.rvTrailers);
        rvDetail.setLayoutManager(layoutManager);
        rvDetail.setAdapter(adapter);
        adapter.notifyDataSetChanged();


        ////////// Reviews

        reviewList = new ArrayList<>();
        reviewAdapter = new ReviewAdapter(this, reviewList);
        RecyclerView.LayoutManager lm = new LinearLayoutManager(getApplicationContext());
        rvReview = findViewById(R.id.rvReview);
        rvReview.setLayoutManager(lm);
        rvReview.setAdapter(reviewAdapter);
        reviewAdapter.notifyDataSetChanged();


        loadJSONTrailers();
        loadJSONReview();


    }


    private void loadJSONTrailers() {
        int movie_id = getIntent().getExtras().getInt("id");
        try {
            if (BuildConfig.THE_MOVIE_DB_API_TOKEN.isEmpty()) {
                Toast.makeText(this, "Please obtain API KEY", Toast.LENGTH_SHORT).show();
                return;
            }
            Client Client = new Client();
            Service apiService = Client.getClient().create(Service.class);
            Call<TrailerResponse> call = apiService.getMovieTrailer(movie_id, BuildConfig.THE_MOVIE_DB_API_TOKEN);
            call.enqueue(new Callback<TrailerResponse>() {
                @Override
                public void onResponse(Call<TrailerResponse> call, Response<TrailerResponse> response) {
                    List<Trailer> trailers = response.body().getResuts();
                    rvDetail.setAdapter(new TrailerAdapter(getApplicationContext(), trailers));
                    rvDetail.smoothScrollToPosition(0);

                }

                @Override
                public void onFailure(Call<TrailerResponse> call, Throwable t) {
                    Log.d("Error", t.getMessage());
                    Toast.makeText(DetailActivity.this, "Error fetching Trailer", Toast.LENGTH_SHORT).show();
                }
            });
        } catch (Exception e) {
            Log.d("Error", e.getMessage());
            Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show();
        }
    }

    private void loadJSONReview() {
        int movie_id = getIntent().getExtras().getInt("id");

        try {
            if (BuildConfig.THE_MOVIE_DB_API_TOKEN.isEmpty()) {
                Toast.makeText(this, "Please obtain API KEY", Toast.LENGTH_SHORT).show();
                return;

            }
            Client Client = new Client();
            Service apiService = Client.getClient().create(Service.class);
            Call<ReviewResponse> call = apiService.getMovieReviews(movie_id, BuildConfig.THE_MOVIE_DB_API_TOKEN);
            call.enqueue(new Callback<ReviewResponse>() {
                @Override
                public void onResponse(Call<ReviewResponse> call, Response<ReviewResponse> response) {
                    List<Review> reviews = response.body().getResults();
                    rvReview.setAdapter(new ReviewAdapter(getApplicationContext(), reviews));
                    rvReview.smoothScrollToPosition(0);
                    Log.d(TAG, "Here>>>>>>>>>>>>>>>>");

                }

                @Override
                public void onFailure(Call<ReviewResponse> call, Throwable t) {
                    Log.d("Error", t.getMessage());
                    Toast.makeText(DetailActivity.this, "Error fetching Review", Toast.LENGTH_SHORT).show();
                }
            });
        } catch (Exception e) {
            Log.d("Error", e.getMessage());
            Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show();
        }
    }

    public void addFavorites() {


        int movie_id = getIntent().getExtras().getInt("id");

        dbHelper = new MovieDbHelper(activity);
        favoriteMovie = new Movie();

        String rate = getIntent().getExtras().getString("vote_average");
        String poster = getIntent().getExtras().getString("poster_path");


        favoriteMovie.setId(movie_id);
        favoriteMovie.setOriginalTitle(movieName.getText().toString().trim());
        favoriteMovie.setPosterPath(poster);
        favoriteMovie.setVoteAverage(Double.parseDouble(rate));
        favoriteMovie.setOverview(synopsis.getText().toString().trim());
        favoriteMovie.setReleaseDate(releaseDate.getText().toString().trim());


        dbHelper.addFavorites(favoriteMovie);
        Log.d(TAG, "Added fav.....");


    }

    private void removeFromFavorites(int id) {


        getApplicationContext().getContentResolver().delete(MovieContract.MovieEntry.CONTENT_URI, MovieContract.MovieEntry.COLUMN_MOVIE_ID + " = ?",
                new String[]{String.valueOf(id)});
    }

    private boolean checkFavoriteMovie(int id) {
        Cursor cursor = activity.getContentResolver().query(MovieContract.MovieEntry.CONTENT_URI, null, MovieContract.MovieEntry.COLUMN_MOVIE_ID + " = " + id, null, null);
        assert cursor != null;
        if (cursor.getCount() <= 0) {
            cursor.close();
            return false;
        }
        cursor.close();
        return true;
    }


}

ReviewAdapter


    public class ReviewAdapter extends 
    RecyclerView.Adapter<ReviewAdapter.MyViewHolder>{

    private Context mContext;
    private List<Review> reviewsList;


    public ReviewAdapter(Context mContext, List<Review> reviewsList){


        this.mContext = mContext;
        this.reviewsList = reviewsList;
    }

    @Override
    public ReviewAdapter.MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i){
        View view = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.review, viewGroup, false);

        return new MyViewHolder(view);

    }
    @Override
    public void onBindViewHolder(final ReviewAdapter.MyViewHolder holder, int i){
        holder.reviewAuthor.setText(reviewsList.get(i).getAuthor());
        holder.reviewContent.setText(reviewsList.get(i).getContent());

    }

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

    }
    public class MyViewHolder extends RecyclerView.ViewHolder{

        TextView reviewAuthor;
        TextView reviewContent;


        public MyViewHolder(View view){
            super(view);
            reviewAuthor = view.findViewById(R.id.review_author);
            reviewContent = view.findViewById(R.id.review_content);



            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    int pos = getAdapterPosition();
                    if(pos != RecyclerView.NO_POSITION){
                        String author = reviewsList.get(pos).getAuthor();
                        String content  = reviewsList.get(pos).getContent();

                        reviewAuthor.setText(author);
                        reviewContent.setText(content);

                    }
                }
            });
        }
    }

}

任何建议都非常感谢我的问题是recyclerview不显示任何数据，但它确实用JSON中的端点显示它们。我也可以链接我的 github，但你需要获取 another API KEY from here 。

我的github链接是here

非常感谢。

Answer 1

您的 RecyclerView 高度可能被评估为“零”。

为了调试此问题，您可以将固定 android:layout_height 设置为某个更大的固定值。