java.lang.NullPointerException：尝试在空对象引用上调用接口方法（*）

Question

在我的应用程序的开发过程中，我遇到了此错误。 因此，我的应用程序由一个recyclerView和一个浮动操作按钮组成，每个recyclerView上都有一个cardViews列表，然后每个Card视图都有一些文本视图以及一个编辑按钮和一个删除按钮。 我试图使用recyclerViewAdapter类-这是一个非活动类-使用对话框片段来调用编辑按钮，这是完整的错误消息：

2019-05-15 02:21:11.063 12260-12260/com.hitham.miscarros E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.hitham.miscarros, PID: 12260
    java.lang.NullPointerException: Attempt to invoke interface method 'void com.hitham.miscarros.Fragments.EditPickerFragment$OnInputListener.sendShit(java.lang.String, java.lang.String, java.lang.String, java.lang.String)' on a null object reference
        at com.hitham.miscarros.Fragments.EditPickerFragment$2.onClick(EditPickerFragment.java:92)
        at android.view.View.performClick(View.java:6913)
        at android.view.View.performClickInternal(View.java:6890)
        at android.view.View.access$3200(View.java:792)
        at android.view.View$PerformClick.run(View.java:27158)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:209)
        at android.app.ActivityThread.main(ActivityThread.java:7021)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:486)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:872)

这是此错误所涉及的RecyclerViewAdapter类段：

 public void editCar(Cars car)
        {
            DialogFragment fragment = new com.hitham.miscarros.Fragments.EditPickerFragment();
            fragment.show(((FragmentActivity)context).getSupportFragmentManager(),"edit car picker fragment");
.
.
.
.
.

       }

            @Override
            public void sendShit(String carManuf, String carName, String carModel, String carImage) {
                DatabaseHandler db = new DatabaseHandler(context);
                Cars car = new Cars();
                car.setCarID(getAdapterPosition());
                if(carManuf != null)
                    car.setCarManuf(carManuf);
                if(carName != null)
                    car.setCarName(carName);
                if(carModel != null)
                    car.setCarModel(carModel);
                if(carImage != null)
                    car.setCarImage(carImage);
                db.updateCars(car);
                notifyItemChanged(getAdapterPosition(), car);
                dialog.dismiss();
                Intent myIntent = new Intent(context,ListActivity.class);
                context.startActivity(myIntent);
                ((Activity)context).finish();
                ((Activity)context).finish();
            }

这是editPickerFragment类：

package com.hitham.miscarros.Fragments;

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.DialogFragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;

import com.hitham.miscarros.Model.Cars;
import com.hitham.miscarros.R;

import static android.app.Activity.RESULT_OK;

public class EditPickerFragment extends DialogFragment {
    public interface OnInputListener {
        void sendShit(String carManuf, String carName, String carModel, String carImage);
    }
    public OnInputListener onInputListener;
    private static final int REQUEST_IMAGE_CAPTURE = 7;
    private Button imageBu;
    private Button submitBu;
    private ImageView carImage;
    private EditText carManuf;
    private EditText carName;
    private EditText carModel;
    private String imagePath;
    private TextView carDetails;
    private Cars car;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View myView = LayoutInflater.from(getActivity()).inflate(R.layout.new_car_popup,null);
        carManuf = myView.findViewById(R.id.nCarManuf);
        carName = myView.findViewById(R.id.nCarName);
        carModel = myView.findViewById(R.id.nCarDOB);
        carImage = myView.findViewById(R.id.laImagenaPuta);
        carDetails = myView.findViewById(R.id.carDetails);
        imageBu = myView.findViewById(R.id.addImageID);
        submitBu = myView.findViewById(R.id.addCarID);
        imageBu.setText(R.string.editImageText);
        submitBu.setText(R.string.editCarBu);
        carDetails.setText(R.string.editCarText);
        carManuf.setHint(R.string.manufHint);
        carName.setHint(R.string.nameHint);
        carModel.setHint(R.string.DOBHint);
        imageBu.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try{
                    if (ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE)
                            != PackageManager.PERMISSION_GRANTED){
                        ActivityCompat.requestPermissions(getActivity(), new String[]{
                                        Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE},
                                REQUEST_IMAGE_CAPTURE);
                    }else {
                        Intent galleryIntent = new Intent(Intent.ACTION_PICK, MediaStore.Images
                                .Media.EXTERNAL_CONTENT_URI);
                        startActivityForResult(galleryIntent,REQUEST_IMAGE_CAPTURE);
                    }
                }catch (Exception e)
                {
                    e.printStackTrace();
                }

            }
        });
        submitBu.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String manuf = carManuf.getText().toString();
                String name = carName.getText().toString();
                String model = carModel.getText().toString();
                onInputListener.sendShit(manuf,name,model,imagePath);
            }
        });
        myView.setBackgroundColor(Color.TRANSPARENT);
        return myView;
    }

    //    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
//
//    }
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode)
        {
            case REQUEST_IMAGE_CAPTURE:
                if (resultCode == RESULT_OK)
                {
                    Uri selectedImage = data.getData();
                    String[] filePathColumn = {MediaStore.Images.Media.DATA};
                    Cursor miCursor = getActivity().getContentResolver().query(selectedImage,filePathColumn,null,null,null);
                    miCursor.moveToFirst();
                    int columnIndex = miCursor.getColumnIndex(filePathColumn[0]);
                    imagePath = miCursor.getString(columnIndex);
                    miCursor.close();
                    Bitmap laImagenaPuta = BitmapFactory.decodeFile(imagePath);
                    carImage.setImageBitmap(laImagenaPuta);
                }
        }
    }
    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        try{
            onInputListener = (OnInputListener) getActivity();
        }catch (ClassCastException e){
            Log.e("maTag","on Attach : class cast exception");
        }
    }

}

当我使用添加按钮（FAB）进行所有操作时，一切正常，因此我确定它与保存到数据库或其他任何东西都没有关系，这只是一个空指针异常，但我不知道如何处理解决这个问题。

P.S，我只包含我认为重要的内容，并对此有所参与，