使用 Serializable - AndroidX 将数据从 RecyclerView 传递到 RecyclerViewMore

Question

当我按下“查看所有项目”时，我想在 Fragment 中将 RecyclerView 中的所有项目显示到另一个 Activity 中的 RecyclerViewMore，但是当我想从 RecyclerViewMore 接收数据时我得到 null

//SectionAdapter.java

    public class AdapterSectionHotTrendingNews extends RecyclerView.Adapter{

    private Context mContext;
    private ArrayList<ModelSectionHotTrendingNews> modelSectionHotTrendingNews;

    public AdapterSectionHotTrendingNews(Context mContext, ArrayList<ModelSectionHotTrendingNews> modelSectionHotTrendingNews) {
        this.mContext = mContext;
        this.modelSectionHotTrendingNews = modelSectionHotTrendingNews;
    }

    @Override
    public SectionHotTrendingNewsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_section_hottrendingnews, null);
        return new SectionHotTrendingNewsViewHolder(v);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

        final SectionHotTrendingNewsViewHolder sectionHotTrendingNewsViewHolder = (SectionHotTrendingNewsViewHolder) holder;
        ModelSectionHotTrendingNews modelSectionHotTrendingNewsX = modelSectionHotTrendingNews.get(position);

        //Set
        sectionHotTrendingNewsViewHolder.TVSectionTitle.setText(modelSectionHotTrendingNewsX.getHeaderTitle());

        ArrayList singleSectionItems = modelSectionHotTrendingNewsX.getAllItemsInSection();
        /*AdapterSingleHotLatestNews.RecyclerViewClickListener listenerLatestNews;
        listenerLatestNews = new AdapterSingleHotLatestNews.RecyclerViewClickListener() {
            @Override
            public void onRowHotLatestNewsClick(View view, int position) {

            }

            @Override
            public void onIconHotLatestNewsClick(View view, int position) {

            }
        };*/
        AdapterSingleHotTrendingNews itemListDataAdapter = new AdapterSingleHotTrendingNews(mContext, singleSectionItems);

        /*itemRowHolder.recycler_view_list.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int action = event.getAction();
                switch (action) {
                    case MotionEvent.ACTION_DOWN:
                        // Disallow ScrollView to intercept touch events.
                        v.getParent().requestDisallowInterceptTouchEvent(true);
                        break;
                    case MotionEvent.ACTION_UP:
                        //Allow ScrollView to intercept touch events once again.
                        v.getParent().requestDisallowInterceptTouchEvent(false);
                        break;
                }
                // Handle RecyclerView touch events.
                v.onTouchEvent(event);
                return true;
            }
        });*/


        sectionHotTrendingNewsViewHolder.BTNHotTrendingNewsMore.setOnClickListener(
                new View.OnClickListener() { @Override public void onClick(View v) {
                    Intent intent = new Intent(mContext, TabMoreHotActivity.class);
                    new Intent().putExtra("MoreNews", modelSectionHotTrendingNews.get(position).getAllItemsInSection());
                mContext.startActivity(intent); } });


        /*Glide.with(mContext)
                .load(feedItem.getImageURL())
                .diskCacheStrategy(DiskCacheStrategy.ALL)
                .centerCrop()
                .error(R.drawable.bg)
                .into(feedListRowHolder.thumbView);*/

        //SetRecyclerView
        sectionHotTrendingNewsViewHolder.RecyclerViewSectionHotTrendingNews.setHasFixedSize(true);
        sectionHotTrendingNewsViewHolder.RecyclerViewSectionHotTrendingNews.setLayoutManager(new LinearLayoutManager(mContext, LinearLayoutManager.HORIZONTAL, false));
        sectionHotTrendingNewsViewHolder.RecyclerViewSectionHotTrendingNews.setAdapter(itemListDataAdapter);
        sectionHotTrendingNewsViewHolder.RecyclerViewSectionHotTrendingNews.setNestedScrollingEnabled(false);
    }

    @Override
    public int getItemCount() {
        int itemCount = modelSectionHotTrendingNews.size();
        return itemCount;
    }

    public class SectionHotTrendingNewsViewHolder extends RecyclerView.ViewHolder {

        protected TextView TVSectionTitle;
        protected ImageView BTNHotTrendingNewsMore;
        protected RecyclerView RecyclerViewSectionHotTrendingNews;
        protected RecyclerView RecyclerViewMoreSectionHotTrendingNews;

        public SectionHotTrendingNewsViewHolder(View itemView) {
            super(itemView);

            TVSectionTitle = (TextView) itemView.findViewById(R.id.TV_SectionTitle);
            BTNHotTrendingNewsMore= (ImageView) itemView.findViewById(R.id.BTN_HotTrendingNewsMore);
            RecyclerViewSectionHotTrendingNews = (RecyclerView) itemView.findViewById(R.id.RecyclerView_Section_HotTrendingNews);
            RecyclerViewMoreSectionHotTrendingNews = (RecyclerView) itemView.findViewById(R.id.RecyclerViewMore_Section_HotTrendingNews);
        }

    }

}

//SingleAdapter.java

    public class AdapterSingleHotTrendingNews extends RecyclerView.Adapter{

    private Context mContext;
    private ArrayList<ModelSingleHotTrendingNews> modelSingleHotTrendingNews;

    public AdapterSingleHotTrendingNews(Context mContext, ArrayList<ModelSingleHotTrendingNews> modelSingleHotTrendingNews) {
        this.mContext = mContext;
        this.modelSingleHotTrendingNews = modelSingleHotTrendingNews;
    }

    //Container
    @Override
    public SingleHotTrendingNewsViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_single_hottrendingnews, null);
        return new SingleHotTrendingNewsViewHolder(v);
    }

    //Fill Container with Model Setter Getter
    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

        final SingleHotTrendingNewsViewHolder singleHotTrendingNewsViewHolder = (SingleHotTrendingNewsViewHolder) holder;
        final ModelSingleHotTrendingNews modelSingleHotTrendingNewsX = modelSingleHotTrendingNews.get(position);

        //Set
        singleHotTrendingNewsViewHolder.TVGameDate.setText(modelSingleHotTrendingNewsX.getGamedate());
        singleHotTrendingNewsViewHolder.TVGameDescription.setText(modelSingleHotTrendingNewsX.getGamedescription());
        singleHotTrendingNewsViewHolder.IMGGameImage.setImageResource(modelSingleHotTrendingNewsX.getGameimage());



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

                final Boolean booltrendingnewssaving = modelSingleHotTrendingNewsX.getTrendingnewssaving();

                final int id = modelSingleHotTrendingNewsX.getId();

                if (booltrendingnewssaving == true){
                    Toast.makeText(v.getContext(), "Turn Off Saved News " + id, Toast.LENGTH_SHORT).show();
                    singleHotTrendingNewsViewHolder.ICONHotTrendingNewsSaving.setImageResource(R.drawable.saved_off);
                    modelSingleHotTrendingNewsX.setTrendingnewssaving(false);
                    /*updateSavedNewsSaving("update_newssaving", id, false);*/
                } else if(booltrendingnewssaving == false) {
                    Toast.makeText(v.getContext(), "Turn On Saved News " + id, Toast.LENGTH_SHORT).show();
                    singleHotTrendingNewsViewHolder.ICONHotTrendingNewsSaving.setImageResource(R.drawable.saved_on);
                    modelSingleHotTrendingNewsX.setTrendingnewssaving(true);
                    /*updateSavedNewsSaving("update_newssaving", id, true);*/
                }
            }
        });



       /* Glide.with(mContext)
                .load(feedItem.getImageURL())
                .diskCacheStrategy(DiskCacheStrategy.ALL)
                .centerCrop()
                .error(R.drawable.bg)
                .into(feedListRowHolder.thumbView);*/

        singleHotTrendingNewsViewHolder.ROWHotTrendingNewsContainer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(v.getContext(), modelSingleHotTrendingNews.get(position).getGamedescription(), Toast.LENGTH_SHORT).show();

                //Passing Data to GameDescriptionActivity
                Intent intent = new Intent(mContext, GameDetailActivity.class);
                intent.putExtra("ImagePKG",  modelSingleHotTrendingNews.get(position).getGameimage());
                intent.putExtra("NamePKG",  modelSingleHotTrendingNews.get(position).getGamedate());
                intent.putExtra("UrlPKG",  modelSingleHotTrendingNews.get(position).getId());
                intent.putExtra("DescriptionPKG",  modelSingleHotTrendingNews.get(position).getGamedescription());
                mContext.startActivity(intent);
            }
        });
    }

    @Override
    public int getItemCount() {
        int itemCount = modelSingleHotTrendingNews.size();
        return itemCount;
    }

    public class SingleHotTrendingNewsViewHolder extends RecyclerView.ViewHolder{
        TextView TVGameDate;
        TextView TVGameDescription;
        ImageView IMGGameImage;

        ImageView ICONHotTrendingNewsSaving;
        private RelativeLayout ROWHotTrendingNewsContainer;


        public SingleHotTrendingNewsViewHolder(View itemView) {
            super(itemView);

            TVGameDate = itemView.findViewById(R.id.TV_GameDate);
            TVGameDescription = itemView.findViewById(R.id.TV_GameDescription);
            IMGGameImage = itemView.findViewById(R.id.IMG_GameImage);

            ICONHotTrendingNewsSaving = itemView.findViewById(R.id.ICON_HotTrendingNewsSaving);
            ROWHotTrendingNewsContainer = itemView.findViewById(R.id.ROW_HotTrendingNewsContainer);
        }

    }


}

//ModelSection.java

    public class ModelSectionHotTrendingNews implements Serializable {

    private String headerTitle;
    private ArrayList<ModelSingleHotTrendingNews> allItemsInSection;

    public ModelSectionHotTrendingNews() {
    }

    public String getHeaderTitle() {
        return headerTitle;
    }

    public void setHeaderTitle(String headerTitle) {
        this.headerTitle = headerTitle;
    }

    public ArrayList<ModelSingleHotTrendingNews> getAllItemsInSection() {
        return allItemsInSection;
    }

    public void setAllItemsInSection(ArrayList<ModelSingleHotTrendingNews> allItemsInSection) {
        this.allItemsInSection = allItemsInSection;
    }


}

//ModelSingle.java

    public class ModelSingleHotTrendingNews implements Serializable {

    private int id;
    private String gamedate;
    private String gamedescription;
    private int gameimage;

    private Boolean trendingnewssaving;
    private String value;
    private String message;

    public ModelSingleHotTrendingNews(int id, String gamedate, String gamedescription, int gameimage, Boolean trendingnewssaving, String value, String message) {
        this.id = id;
        this.gamedate = gamedate;
        this.gamedescription = gamedescription;
        this.gameimage = gameimage;
        this.trendingnewssaving = trendingnewssaving;
        this.value = value;
        this.message = message;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getGamedate() {
        return gamedate;
    }

    public void setGamedate(String gamedate) {
        this.gamedate = gamedate;
    }

    public String getGamedescription() {
        return gamedescription;
    }

    public void setGamedescription(String gamedescription) {
        this.gamedescription = gamedescription;
    }

    public int getGameimage() {
        return gameimage;
    }

    public void setGameimage(int gameimage) {
        this.gameimage = gameimage;
    }

    public Boolean getTrendingnewssaving() {
        return trendingnewssaving;
    }

    public void setTrendingnewssaving(Boolean trendingnewssaving) {
        this.trendingnewssaving = trendingnewssaving;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

//This function SectionAdapter.java is to send data from RecyclerView in Fragment to RecyclerViewMore Activity

    sectionHotTrendingNewsViewHolder.BTNHotTrendingNewsMore.setOnClickListener(
                new View.OnClickListener() { @Override public void onClick(View v) {
                    Intent intent = new Intent(mContext, TabMoreHotActivity.class);
                    new Intent().putExtra("MoreNews", modelSectionHotTrendingNews.get(position).getAllItemsInSection());
                mContext.startActivity(intent); } });

//我在那些 RecyclerViews 中使用相同的 Model 但不同的 Adapter //我在 Fragment AdapterSection.java,AdapterSingle.java,ModelSection.java,ModelSingle.java中使用RecyclerView //我在Activity中使用RecyclerViewMore AdapterMoreSection.java,AdapterMoreSingle.java,ModelSection.java,ModelSingle.java //RecyclerViewMoreActivity.java

    public class TabMoreHotActivity extends AppCompatActivity {



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

        AdapterMoreSectionHotTrendingNews adapterMoreSectionHotTrendingNews;
        ArrayList<ModelSectionHotTrendingNews> modelSectionHotTrendingNews = null;
        Bundle bundle = getIntent().getExtras();
        if(bundle!=null)
        {
            modelSectionHotTrendingNews = (ArrayList<ModelSectionHotTrendingNews>) bundle.getSerializable("MoreNews");
        }


        //1
        RecyclerView RecyclerViewMoreSingleHotTrendingNews = findViewById(R.id.RecyclerViewMore_Single_HotTrendingNews);
        RecyclerViewMoreSingleHotTrendingNews.setHasFixedSize(true);
        adapterMoreSectionHotTrendingNews = new AdapterMoreSectionHotTrendingNews(this, modelSectionHotTrendingNews);
        RecyclerViewMoreSingleHotTrendingNews.setAdapter(adapterMoreSectionHotTrendingNews);
        RecyclerViewMoreSingleHotTrendingNews.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));



        //Optimized
        RecyclerViewMoreSingleHotTrendingNews.setHasFixedSize(true);
        RecyclerViewMoreSingleHotTrendingNews.setItemViewCacheSize(20);
    }
}

//我收到了这个错误

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.indofun.android.indojoy, PID: 32309
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference
    at com.indofun.android.indojoy.Adapters.AdapterMore_HotTrendingNews.AdapterMoreSectionHotTrendingNews.getItemCount(AdapterMoreSectionHotTrendingNews.java:109)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep1(RecyclerView.java:4042)
    at androidx.recyclerview.widget.RecyclerView.onMeasure(RecyclerView.java:3532)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
    at android.view.View.measure(View.java:23279)
    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at com.android.internal.policy.DecorView.onMeasure(DecorView.java:898)
    at android.view.View.measure(View.java:23279)
    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2873)
    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1910)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2165)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1779)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7810)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:911)
    at android.view.Choreographer.doCallbacks(Choreographer.java:723)
    at android.view.Choreographer.doFrame(Choreographer.java:658)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:897)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6938)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)

//提供对我有很大帮助的代码

//更新

//AdapterMoreSingle

    public class AdapterMoreSingleHotTrendingNews extends RecyclerView.Adapter{

    private Context mContext;
    private ArrayList<ModelSingleHotTrendingNews> modelSingleHotTrendingNews;

    public AdapterMoreSingleHotTrendingNews(Context mContext, ArrayList<ModelSingleHotTrendingNews> modelSingleHotTrendingNews) {
        this.mContext = mContext;
        this.modelSingleHotTrendingNews = modelSingleHotTrendingNews;
    }

    //Container
    @Override
    public SingleMoreHotTrendingNewsViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.itemmore_single_hottrendingnews, null);
        return new SingleMoreHotTrendingNewsViewHolder(v);
    }

    //Fill Container with Model Setter Getter
    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

        final SingleMoreHotTrendingNewsViewHolder singleMoreHotTrendingNewsViewHolder = (SingleMoreHotTrendingNewsViewHolder) holder;
        final ModelSingleHotTrendingNews modelSingleHotTrendingNewsX = modelSingleHotTrendingNews.get(position);

        //Set
        singleMoreHotTrendingNewsViewHolder.TVGameDate.setText(modelSingleHotTrendingNewsX.getGamedate());
        singleMoreHotTrendingNewsViewHolder.TVGameDescription.setText(modelSingleHotTrendingNewsX.getGamedescription());
        singleMoreHotTrendingNewsViewHolder.IMGGameImage.setImageResource(modelSingleHotTrendingNewsX.getGameimage());



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

                final Boolean booltrendingnewssaving = modelSingleHotTrendingNewsX.getTrendingnewssaving();

                final int id = modelSingleHotTrendingNewsX.getId();

                if (booltrendingnewssaving == true){
                    Toast.makeText(v.getContext(), "Turn Off Saved News " + id, Toast.LENGTH_SHORT).show();
                    singleMoreHotTrendingNewsViewHolder.ICONHotTrendingNewsSaving.setImageResource(R.drawable.saved_off);
                    modelSingleHotTrendingNewsX.setTrendingnewssaving(false);
                    /*updateSavedNewsSaving("update_newssaving", id, false);*/
                } else if(booltrendingnewssaving == false) {
                    Toast.makeText(v.getContext(), "Turn On Saved News " + id, Toast.LENGTH_SHORT).show();
                    singleMoreHotTrendingNewsViewHolder.ICONHotTrendingNewsSaving.setImageResource(R.drawable.saved_on);
                    modelSingleHotTrendingNewsX.setTrendingnewssaving(true);
                    /*updateSavedNewsSaving("update_newssaving", id, true);*/
                }
            }
        });



       /* Glide.with(mContext)
                .load(feedItem.getImageURL())
                .diskCacheStrategy(DiskCacheStrategy.ALL)
                .centerCrop()
                .error(R.drawable.bg)
                .into(feedListRowHolder.thumbView);*/

        singleMoreHotTrendingNewsViewHolder.ROWHotTrendingNewsContainer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(v.getContext(), modelSingleHotTrendingNews.get(position).getGamedescription(), Toast.LENGTH_SHORT).show();

                //Passing Data to GameDescriptionActivity
                Intent intent = new Intent(mContext, GameDetailActivity.class);
                intent.putExtra("ImagePKG",  modelSingleHotTrendingNews.get(position).getGameimage());
                intent.putExtra("NamePKG",  modelSingleHotTrendingNews.get(position).getGamedate());
                intent.putExtra("UrlPKG",  modelSingleHotTrendingNews.get(position).getId());
                intent.putExtra("DescriptionPKG",  modelSingleHotTrendingNews.get(position).getGamedescription());
                mContext.startActivity(intent);
            }
        });
    }

    @Override
    public int getItemCount() {
        int itemCount = modelSingleHotTrendingNews.size();
        return itemCount;
    }

    public class SingleMoreHotTrendingNewsViewHolder extends RecyclerView.ViewHolder{
        TextView TVGameDate;
        TextView TVGameDescription;
        ImageView IMGGameImage;

        ImageView ICONHotTrendingNewsSaving;
        private RelativeLayout ROWHotTrendingNewsContainer;


        public SingleMoreHotTrendingNewsViewHolder(View itemView) {
            super(itemView);

            TVGameDate = itemView.findViewById(R.id.TV_GameDate);
            TVGameDescription = itemView.findViewById(R.id.TV_GameDescription);
            IMGGameImage = itemView.findViewById(R.id.IMG_GameImage);

            ICONHotTrendingNewsSaving = itemView.findViewById(R.id.ICON_HotTrendingNewsSaving);
            ROWHotTrendingNewsContainer = itemView.findViewById(R.id.ROW_HotTrendingNewsContainer);
        }

    }


}

//UPDATED2 AdapterSectionMore.java

public class AdapterMoreSectionHotTrendingNews extends RecyclerView.Adapter {

private Context mContext;
private ArrayList<ModelSectionHotTrendingNews> modelSectionHotTrendingNews;

public AdapterMoreSectionHotTrendingNews(Context mContext, ArrayList<ModelSectionHotTrendingNews> modelSectionHotTrendingNews) {
    this.mContext = mContext;
    this.modelSectionHotTrendingNews = modelSectionHotTrendingNews;
}

@Override
public SectionMoreHotTrendingNewsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.itemmore_section_hottrendingnews, null);
    return new SectionMoreHotTrendingNewsViewHolder(v);
}


@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

    final SectionMoreHotTrendingNewsViewHolder sectionMoreHotTrendingNewsViewHolder = (SectionMoreHotTrendingNewsViewHolder) holder;
    ModelSectionHotTrendingNews modelSectionHotTrendingNewsX = modelSectionHotTrendingNews.get(position);

    //Set
    sectionMoreHotTrendingNewsViewHolder.TVSectionTitle.setText(modelSectionHotTrendingNewsX.getHeaderTitle());
    // here you have to change your ArrayList to ArrayList<ModelSingleHotTrendingNews>
    ArrayList<ModelSingleHotTrendingNews> singleSectionItems = modelSectionHotTrendingNewsX.getAllItemsInSection();

    /*AdapterSingleHotLatestNews.RecyclerViewClickListener listenerLatestNews;
    listenerLatestNews = new AdapterSingleHotLatestNews.RecyclerViewClickListener() {
        @Override
        public void onRowHotLatestNewsClick(View view, int position) {

        }

        @Override
        public void onIconHotLatestNewsClick(View view, int position) {

        }
    };*/
    AdapterMoreSingleHotTrendingNews itemListDataAdapter = new AdapterMoreSingleHotTrendingNews(mContext, singleSectionItems);

    /*itemRowHolder.recycler_view_list.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            int action = event.getAction();
            switch (action) {
                case MotionEvent.ACTION_DOWN:
                    // Disallow ScrollView to intercept touch events.
                    v.getParent().requestDisallowInterceptTouchEvent(true);
                    break;
                case MotionEvent.ACTION_UP:
                    //Allow ScrollView to intercept touch events once again.
                    v.getParent().requestDisallowInterceptTouchEvent(false);
                    break;
            }
            // Handle RecyclerView touch events.
            v.onTouchEvent(event);
            return true;
        }
    });*/


    final String sectionTitle = modelSectionHotTrendingNewsX.getHeaderTitle();
    sectionMoreHotTrendingNewsViewHolder.BTNHotTrendingNewsMore.setOnClickListener(
            new View.OnClickListener() {
                @Override public void onClick(View v) {
                    //More IN RecyclerViewMore
                }
            });


    /*Glide.with(mContext)
            .load(feedItem.getImageURL())
            .diskCacheStrategy(DiskCacheStrategy.ALL)
            .centerCrop()
            .error(R.drawable.bg)
            .into(feedListRowHolder.thumbView);*/

    //SetRecyclerView
    sectionMoreHotTrendingNewsViewHolder.RecyclerViewMoreSectionHotTrendingNews.setHasFixedSize(true);
    sectionMoreHotTrendingNewsViewHolder.RecyclerViewMoreSectionHotTrendingNews.setLayoutManager(new LinearLayoutManager(mContext, LinearLayoutManager.HORIZONTAL, false));
    sectionMoreHotTrendingNewsViewHolder.RecyclerViewMoreSectionHotTrendingNews.setAdapter(itemListDataAdapter);
    sectionMoreHotTrendingNewsViewHolder.RecyclerViewMoreSectionHotTrendingNews.setNestedScrollingEnabled(false);
}

@Override
public int getItemCount() {
    int itemCount = modelSectionHotTrendingNews.size();
    return itemCount;
}

public class SectionMoreHotTrendingNewsViewHolder extends RecyclerView.ViewHolder {

    protected TextView TVSectionTitle;
    protected ImageView BTNHotTrendingNewsMore;
    protected RecyclerView RecyclerViewMoreSectionHotTrendingNews;

    public SectionMoreHotTrendingNewsViewHolder(View itemView) {
        super(itemView);

        TVSectionTitle = (TextView) itemView.findViewById(R.id.TV_SectionTitle);
        BTNHotTrendingNewsMore= (ImageView) itemView.findViewById(R.id.BTN_HotTrendingNewsMore);
        RecyclerViewMoreSectionHotTrendingNews = (RecyclerView) itemView.findViewById(R.id.RecyclerViewMore_Section_HotTrendingNews);
    }

}

}

Answer 1

因为您将null modelSectionHotTrendingNews 传递给您的适配器。

你只需要在你的TabMoreHotActivityinitialize你的ArrayList

还有一件事你必须在set adapter之前set layout manger到你的recycler view。

public class TabMoreHotActivity extends AppCompatActivity {

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

    AdapterMoreSectionHotTrendingNews adapterMoreSectionHotTrendingNews;
    // here you have to initialize it 
    ArrayList<ModelSectionHotTrendingNews> modelSectionHotTrendingNews = new ArrayList<>();
    Bundle bundle = getIntent().getExtras();
    if(bundle!=null)
    {
        modelSectionHotTrendingNews = (ArrayList<ModelSectionHotTrendingNews>) bundle.getSerializable("MoreNews");
    }


    //1
    RecyclerView RecyclerViewMoreSingleHotTrendingNews = findViewById(R.id.RecyclerViewMore_Single_HotTrendingNews);
    RecyclerViewMoreSingleHotTrendingNews.setHasFixedSize(true);
    adapterMoreSectionHotTrendingNews = new AdapterMoreSectionHotTrendingNews(this, modelSectionHotTrendingNews);

    // here have to set layout manager before set adapter
    RecyclerViewMoreSingleHotTrendingNews.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));

    // and then you have to set adapter to recyclerview 
 RecyclerViewMoreSingleHotTrendingNews.setAdapter(adapterMoreSectionHotTrendingNews);




    //Optimized
    RecyclerViewMoreSingleHotTrendingNews.setHasFixedSize(true);
    RecyclerViewMoreSingleHotTrendingNews.setItemViewCacheSize(20);
   }
}

更新

将ArrayList 中的onBindViewHolder 中的ArrayList<ModelSingleHotTrendingNews> 更改为AdapterMoreSectionHotTrendingNews 中的ArrayList<ModelSingleHotTrendingNews>。

 @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

        final SectionMoreHotTrendingNewsViewHolder sectionMoreHotTrendingNewsViewHolder = (SectionMoreHotTrendingNewsViewHolder) holder;
        ModelSectionHotTrendingNews modelSectionHotTrendingNewsX = modelSectionHotTrendingNews.get(position);

        //Set
        sectionMoreHotTrendingNewsViewHolder.TVSectionTitle.setText(modelSectionHotTrendingNewsX.getHeaderTitle());
        // here you have to change your ArrayList to ArrayList<ModelSingleHotTrendingNews> 
        ArrayList<ModelSingleHotTrendingNews> singleSectionItems = modelSectionHotTrendingNewsX.getAllItemsInSection();
// reset of your codes here.

Answer 2

对于这个错误

java.lang.NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference

通过@Jakir 的回答，您可以初始化 ArrayList 以使用特定大小（即new ArrayList<>(0);）进行额外点初始化，以减少内存使用量，因为数组列表默认内存中有 10 个对象的大量内存。

或

在 getItem 中检查这个条件

@Override
public int getItemCount() {
    return modelSectionHotTrendingNews != null && modelSectionHotTrendingNews.size();
}

它将解决此错误。

用于代码中的可序列化解析

Intent intent = new Intent(mContext, TabMoreHotActivity.class);
// here you create put extra in new intent not the intent that you created

new Intent().putExtra("MoreNews", modelSectionHotTrendingNews.get(position).getAllItemsInSection());
mContext.startActivity(intent);

改成

Intent intent = new Intent(mContext, TabMoreHotActivity.class);
// here you create put extra in new intent not the intent that you created

intent.putExtra("MoreNews", modelSectionHotTrendingNews.get(position).getAllItemsInSection());
mContext.startActivity(intent);

编码愉快.... ;)