RecyclerView 适配器变为 null-解网

问：

我在我的应用程序中嵌套了 RecyclerViews，我从中填充问题及其各自的答案。问题是当我尝试附加图像时，Child RecyclerView 适配器以某种方式获得 null。我尝试解决它，但没有成功。我希望有人能帮忙。

我的第一个适配器：

public class QuestionsAdapter extends 
RecyclerView.Adapter<QuestionsAdapter.QuestionsViewHolder> 
implements Parcelable {

ArrayList<QuestionsData> questionsDataArrayList;
Context context;
OptionsAdapter optionsAdapter;
Fragment fragment;

public QuestionsAdapter(Context context,ArrayList<QuestionsData>questionsDataArrayList,Fragment fragment) {
    this.questionsDataArrayList = questionsDataArrayList;
    this.context = context;
    this.fragment = fragment;
}

protected QuestionsAdapter(Parcel in) {
}

public static final Creator<QuestionsAdapter> CREATOR = new Creator<QuestionsAdapter>() {
    @Override
    public QuestionsAdapter createFromParcel(Parcel in) {
        return new QuestionsAdapter(in);
    }

    @Override
    public QuestionsAdapter[] newArray(int size) {
        return new QuestionsAdapter[size];
    }
};

@NonNull
@Override
public QuestionsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view;
    view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_questions_item, parent, false);
    return new QuestionsViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull QuestionsViewHolder holder, int position) {
    holder.question_title.setText(questionsDataArrayList.get(position).getQuesiton());
    optionsAdapter = new OptionsAdapter(context, questionsDataArrayList.get(position).getQuestionOptionsArrayList()
            , questionsDataArrayList.get(position).getId(), (QuestionsFragment) fragment);
    holder.questions_option_recyclerView.setLayoutManager(new GridLayoutManager(context, 1));

    GridLayoutManager gridLayoutManager = new GridLayoutManager(context, 1) {
        @Override
        public boolean canScrollVertically() {
            return false;
        }
    };
    holder.questions_option_recyclerView.setLayoutManager(gridLayoutManager);
    holder.questions_option_recyclerView.setItemViewCacheSize(questionsDataArrayList.size());
    holder.questions_option_recyclerView.setAdapter(optionsAdapter);
}

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

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel parcel, int i) {
}

class QuestionsViewHolder extends RecyclerView.ViewHolder {
    private final TextView question_title;
    private final RecyclerView questions_option_recyclerView;

    QuestionsViewHolder(@NonNull View itemView) {
        super(itemView);
        question_title = itemView.findViewById(R.id.question_title);
        questions_option_recyclerView = itemView.findViewById(R.id.questions_option_recyclerView);
    }
}

public void setImage(ArrayList<ImagePathModel> imagesList) {
    ArrayList<Uri> images = new ArrayList<>();
    for (ImagePathModel image : imagesList
    ) {
        images.add(image.getUri());
    }
    optionsAdapter.updateImages(images);

}
}

第二个适配器：

public class OptionsAdapter extends 
RecyclerView.Adapter<RecyclerView.ViewHolder> {

ArrayList<QuestionOptions> questionOptionsArrayList;
Context context;
String currentQuestionID;
public ImagesRecyclerViewAdapter imagesRecyclerViewAdapter;
QuestionAnswerModel.Answers answers;
QuestionsFragment fragment;
SharedPreferenceHandler sharedPreferenceHandler;


public OptionsAdapter(Context context, ArrayList<QuestionOptions> questionOptionsArrayList, String currentQuestionID, QuestionsFragment fragment) {
    this.questionOptionsArrayList = questionOptionsArrayList;
    this.context = context;
    this.currentQuestionID = currentQuestionID;
    this.fragment = fragment;
    answers = new QuestionAnswerModel.Answers();
    sharedPreferenceHandler = new SharedPreferenceHandler(context);
}

@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view;
    if (viewType == 1) { // for call layout
        view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_answer_options, parent, false);
        return new OptionsViewHolder(view);
    } else if (viewType == 2) { // for email layout
        view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_text_item, parent, false);
        return new TextViewHolder(view);
    } else {
        view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_images_item, parent, false);
        return new ImagesViewHolder(view);
    }
}

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

    if ((questionOptionsArrayList.get(position).getInputType().equalsIgnoreCase("image"))) {
        imagesRecyclerViewAdapter = new ImagesRecyclerViewAdapter(context, answers.getImages());
        ((ImagesViewHolder) holder).recyclerView_images.setAdapter(imagesRecyclerViewAdapter);
    } else if (questionOptionsArrayList.get(position).getInputType().equalsIgnoreCase("radio")) {
        if (questionOptionsArrayList.get(position).getValue().equalsIgnoreCase("1")) {
            questionOptionsArrayList.get(position).setIsRadioButtonSelected(true);
        }
        ((OptionsViewHolder) holder).answer_option.setText(questionOptionsArrayList.get(position).getOption());
        ((OptionsViewHolder) holder).answer_option.setChecked(questionOptionsArrayList.get(position).getIsRadioButtonSelected());
    } else if ((questionOptionsArrayList.get(position).getInputType().equalsIgnoreCase("text"))) {
        ((TextViewHolder) holder).option_title.setText(questionOptionsArrayList.get(position).getOption());
        ((TextViewHolder) holder).et_answer.setHint("Enter Value");
        if (!questionOptionsArrayList.get(position).getValue().isEmpty()) {
            ((TextViewHolder) holder).et_answer.setText(questionOptionsArrayList.get(position).getValue());
        }
    }
}

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

@Override
public int getItemViewType(int position) {
    if (questionOptionsArrayList.get(position).getInputType().equalsIgnoreCase("radio")) {
        return 1;
    } else if (questionOptionsArrayList.get(position).getInputType().equalsIgnoreCase("text")) {
        return 2;
    } else {
        return 3;
    }
}

class OptionsViewHolder extends RecyclerView.ViewHolder {
    CheckBox answer_option;

    OptionsViewHolder(@NonNull View itemView) {
        super(itemView);

        answer_option = itemView.findViewById(R.id.answer_option);
        
        answer_option.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    questionOptionsArrayList.get(getAdapterPosition()).setIsRadioButtonSelected(answer_option.isChecked());
                    answers.setQuestion_id(currentQuestionID);
                    answers.getType().add(questionOptionsArrayList.get(getAdapterPosition()).getInputType());
                    answers.getOption_id().add(questionOptionsArrayList.get(getAdapterPosition()).getId());
                    answers.getValue().add("1");
                    searchDeleteAndAddItem(currentQuestionID,
                            questionOptionsArrayList.get(getAdapterPosition()).getId(),
                            questionOptionsArrayList.get(getAdapterPosition()).getInputType(),
                            "1");
                    //   searchAndAddItem(answers);
                } else {
                    questionOptionsArrayList.get(getAdapterPosition()).setIsRadioButtonSelected(answer_option.isChecked());
                    answers.setQuestion_id(currentQuestionID);
                    answers.getType().add(questionOptionsArrayList.get(getAdapterPosition()).getInputType());
                    answers.getOption_id().add(questionOptionsArrayList.get(getAdapterPosition()).getId());
                    answers.getValue().add("0");
                    searchDeleteAndAddItem(currentQuestionID,
                            questionOptionsArrayList.get(getAdapterPosition()).getId(),
                            questionOptionsArrayList.get(getAdapterPosition()).getInputType(),
                            "0");
                }
            }
        });

    }
}

class TextViewHolder extends RecyclerView.ViewHolder {

    private final EditText et_answer;
    private final TextView option_title;

    TextViewHolder(@NonNull View itemView) {
        super(itemView);
        et_answer = itemView.findViewById(R.id.et_answer);
        option_title = itemView.findViewById(R.id.option_title);
        et_answer.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                if (s.length() > 0) {
                    answers.setQuestion_id(currentQuestionID);
                    answers.getType().add(questionOptionsArrayList.get(getAdapterPosition()).getInputType());
                    answers.getOption_id().add(questionOptionsArrayList.get(getAdapterPosition()).getId());
                    answers.getValue().add(et_answer.getText().toString());
                    searchDeleteAndAddItem(currentQuestionID, questionOptionsArrayList.get(getAdapterPosition()).getId(), questionOptionsArrayList.get(getAdapterPosition()).getInputType(),
                            s.toString());
                } else {
                    removeItem(questionOptionsArrayList.get(getAdapterPosition()).getId());
                }

            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });
    }
}

class ImagesViewHolder extends RecyclerView.ViewHolder {

    private final RecyclerView recyclerView_images;
    private final MaterialButton btn_add_images;


    ImagesViewHolder(@NonNull View itemView) {
        super(itemView);
        btn_add_images = itemView.findViewById(R.id.btn_add_images);
        recyclerView_images = itemView.findViewById(R.id.recyclerView_images);
        recyclerView_images.hasFixedSize();
        recyclerView_images.setLayoutManager(new GridLayoutManager(context, 3));
        btn_add_images.setOnClickListener(v -> {
                    sharedPreferenceHandler.setString("questionID", currentQuestionID);
                    sharedPreferenceHandler.setString("inputType", questionOptionsArrayList.get(getAdapterPosition()).getInputType());
                    sharedPreferenceHandler.setString("ID", questionOptionsArrayList.get(getAdapterPosition()).getId());
                  
                    Intent intent = new Intent(context, EditImageActivity.class);
                    intent.addFlags(Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION);
                    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
                    fragment.startActivityForResult(intent, 300);
                }
        );
    }
}

public void searchAndAddItem(QuestionAnswerModel.Answers answer) {
    Constants.CURRENT_INSPECTION.answersArrayList.add(answer);
}

public void searchDeleteAndAddItem(String questionID, String optionID, String inputType, String value) {

    boolean newQuestion = false;
    if (Constants.CURRENT_INSPECTION.answersArrayList.size() == 0) {
        Constants.CURRENT_INSPECTION.answersArrayList.add(answers);
    } else
        for (int index = 0; index < Constants.CURRENT_INSPECTION.answersArrayList.size(); index++) {
            if (Constants.CURRENT_INSPECTION.answersArrayList.get(index).getQuestion_id().equalsIgnoreCase(questionID)) {
                for (int i = 0; i < Constants.CURRENT_INSPECTION.answersArrayList.get(index).getOption_id().size(); i++) {
                    if (Constants.CURRENT_INSPECTION.answersArrayList.get(index).getOption_id().get(i).equalsIgnoreCase(optionID)) {
                        Constants.CURRENT_INSPECTION.answersArrayList.get(index).getOption_id().remove(i);
                        Constants.CURRENT_INSPECTION.answersArrayList.get(index).getValue().remove(i);
                        Constants.CURRENT_INSPECTION.answersArrayList.get(index).getType().remove(i);
                        break;
                    }
                }
                Constants.CURRENT_INSPECTION.answersArrayList.get(index).getOption_id().add(optionID);
                Constants.CURRENT_INSPECTION.answersArrayList.get(index).getType().add(inputType);
                Constants.CURRENT_INSPECTION.answersArrayList.get(index).getValue().add(value);
            } else {
                newQuestion = true;
            }
        }
    if (newQuestion) {
        Constants.CURRENT_INSPECTION.answersArrayList.add(answers);
    }


}


public void removeItem(String optionID) {
    for (int index = 0; index < answers.getOption_id().size(); index++) {
        if (answers.getOption_id().get(index).equalsIgnoreCase(optionID)) {
            answers.getOption_id().remove(index);
            answers.getType().remove(index);
            answers.getValue().remove(index);
        }
    }

}

public void updateImages(ArrayList<Uri> uris) {
    String questionID = sharedPreferenceHandler.getString("questionID");
    String inputType = sharedPreferenceHandler.getString("inputType");
    String ID = sharedPreferenceHandler.getString("ID");
    imagesRecyclerViewAdapter.notifyChange(uris);

}

}

第三个适配器：

public class ImagesRecyclerViewAdapter extends RecyclerView.Adapter<ImagesRecyclerViewAdapter.ViewHolder> {
ArrayList<Uri> images;
Context context;

public ImagesRecyclerViewAdapter(Context context, ArrayList<Uri> images) {
    this.images = images;
    this.context = context;
}

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

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
    try {

        holder.images_item.setImageBitmap(MediaStore.Images.Media.getBitmap(context.getContentResolver(), images.get(position)));
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public void notifyChange(ArrayList<Uri> images) {
    images.addAll(images);
    this.notifyDataSetChanged();
}

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

public class ViewHolder extends RecyclerView.ViewHolder {
    ImageView images_item, iv_close_image;

    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        images_item = itemView.findViewById(R.id.images_item);
        iv_close_image = itemView.findViewById(R.id.iv_close_image);
        iv_close_image.setOnClickListener(view -> {
            images.remove(getAdapterPosition());
            notifyDataSetChanged();
        });
        images_item.setOnClickListener(view -> {
            Intent viewIntent = new Intent(context, ImageViewerActivity.class);
            viewIntent.putExtra("uri", images.get(getAdapterPosition()).toString());
            context.startActivity(viewIntent);
        });

    }
}
}

日志：：我正面临这个问题。

2021-11-18 16：09：33.641 20945-20945/com.arcore.properscan E/AndroidRuntime：致命异常：main 进程：com.arcore.properscan，PID：20945 java.lang.RuntimeException：传递结果 ResultInfo{who=null， request=490889150， result=-1， data=Intent { （具有 extras） }} 到活动 {com.arcore.properscan/com.arcore.properscan.Activities.InspectionSubCategoryActivity}： java.lang.NullPointerException：尝试调用虚拟方法“void” com.arcore.properscan.Adapters.ImagesRecyclerViewAdapter.notifyChange（java.util.ArrayList）' 在 null 对象引用上在 android.app.ActivityThread.deliverResults（ActivityThread.java：4626）在 android.app.ActivityThread.handleSendResult（ActivityThread.java：4670）在 android.app.ActivityThread.-wrap19（未知来源：0）在 android.app.ActivityThread$H.handleMessage（ActivityThread.java：1829）在 android.os.Handler.dispatchMessage（Handler.java：106）在android.os.Looper.loop（Looper.java：198）在 android.app.ActivityThread.main（ActivityThread.java：7055）在 java.lang.reflect.Method.invoke（本机方法）在 com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run（RuntimeInit.java：523）在 com.android.internal.os.ZygoteInit.main（ZygoteInit.java：836）原因：java.lang.NullPointerException：尝试调用虚拟方法“void” com.arcore.properscan.Adapters.ImagesRecyclerViewAdapter.notifyChange（java.util.ArrayList）' 在 null 对象引用上在 com.arcore.properscan.Adapters.OptionsAdapter.updateImages（OptionsAdapter.java：295）在com.arcore.properscan.Adapters.QuestionsAdapter.setImage（QuestionsAdapter.java：114）在 com.arcore.properscan.Fragments.QuestionsFragment.onActivityResult（QuestionsFragment.java：116）在 androidx.fragment.app.FragmentManager$9.onActivityResult（FragmentManager.java：2905）在 androidx.fragment.app.FragmentManager$9.onActivityResult（FragmentManager.java：2885）在 androidx.activity.result.ActivityResultRegistry.doDispatch（ActivityResultRegistry.java：392）在 androidx.activity.result.ActivityResultRegistry.dispatchResult（ActivityResultRegistry.java：351）在 androidx.activity.ComponentActivity.onActivityResult（ComponentActivity.java：647）在 androidx.fragment.app.FragmentActivity.onActivityResult（FragmentActivity.java：164）在 android.app.Activity.dispatchActivityResult（Activity.java：7634）在 android.app.ActivityThread.deliverResults（ActivityThread.java：4622）在 android.app.ActivityThread.handleSendResult（ActivityThread.java：4670）在 android.app.ActivityThread.-wrap19（未知来源：0）在 android.app.ActivityThread$H.handleMessage（ActivityThread.java：1829）在 android.os.Handler.dispatchMessage（Handler.java：106）在android.os.Looper.loop（Looper.java：198）在 android.app.ActivityThread.main（ActivityThread.java：7055）在 java.lang.reflect.Method.invoke（本机方法）在 com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run（RuntimeInit.java：523）在 com.android.internal.os.ZygoteInit.main（ZygoteInit.java：836）

安卓 android-recyclerview nullpointerexception

0赞 grabarz121 11/18/2021

您收到的数据为 null。我猜这是相机拍摄的图像。onActivityResult()

0赞 avalerio 11/18/2021

你真的把这个传给了另一个人吗？First AdapterParcelableAdapterActivity

答： 暂无答案

上一个：java.lang.NullPointerException： mainRvRef 不能为 null ，其中 mainRvRef 引用的是 reyclerView

下一个：公共类 Adpter、onCreateViewHolder、MediaPlayer 的 NullPointerException

RecyclerView 适配器变为 null

RecyclerView Adapter becomes null

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