我有一个应用程序来辩论，为此我使用了java和xml。应用程序显示了一个列表，其中包含用户添加的关于应用程序中发布的主题的论点。当用户想辩论时，他点击一个图像视图，显示一个警告对话框，询问他是否真的想反驳。到目前为止，一切都运行得很完美。当用户按下“ok I want to counter”（警报对话框内的按钮）时，问题出现，因为当这样做时，它返回以下错误：“Java .lang.空指针异常：尝试在空对象引用”“上调用接口方法”void Fragments.sendArgument.sendArgument（java.lang.String）.“我应该将参数作为参数发送到另一个片段，以便在此新片段中显示。我正在使用接口将存储参数的变量发送到另一个片段。我将给您留下部分代码，以便您可以帮助我。问候
回收视图

public class adapterArguments extends RecyclerView.Adapter<adapterArguments.ViewHolder> {
    private List<ListArguments> data;
    private LayoutInflater inflater;
    private Context context;
    public String position_selected,argument;
    public static String argument_aux;
    private sendArgument sendArgument;


    public adapterArguments(List<ListArguments> itemList, Context context,sendArgument argument) {
        this.data = itemList;
        this.inflater = LayoutInflater.from(context);
        this.context = context;
        this.sendArgument = argument;

    }

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

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.arguments.setText(data.get(position).getArguments());
        holder.name_user.setText(data.get(position).getName_user());
        holder.date.setText(data.get(position).getDate_arguments());
        holder.position.setText(data.get(position).getPosition());
        position_selected = holder.position.getText().toString();
        if(position_selected.equals("A favor")){
            holder.position.setBackgroundColor(Color.parseColor("#073FD7"));
        }
        else{
            holder.position.setBackgroundColor(Color.parseColor("#FC0C1E"));
        }
        holder.addContrarguments.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder alertDialog = new AlertDialog.Builder(v.getContext());
                alertDialog.setTitle("Añadir un Contrargumento");
                alertDialog.setMessage("¿Quieres añadir un contrargumento a este texto?");
                alertDialog.setPositiveButton("Aceptar", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                argument = holder.arguments.getText().toString();
                                sendArgument.sendArgument(argument);
                                FragmentManager fragmentManager;
                                FragmentTransaction fragmentTransaction;
                                fragmentManager = ((AppCompatActivity)context).getSupportFragmentManager();
                                fragmentTransaction = fragmentManager.beginTransaction();
                                fragmentTransaction.replace(R.id.container, new contrargument());
                                fragmentTransaction.addToBackStack(null);
                                fragmentTransaction.commit();
                            }
                        });
                alertDialog.setNegativeButton("Cancelar", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {

                            }
                        });
                AlertDialog customAlertDialog = alertDialog.create();
                customAlertDialog.show();
            }
        });

    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView arguments,name_user,date,position;
        ImageButton addContrarguments;
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            arguments = itemView.findViewById(R.id.arguments_posted);
            name_user = itemView.findViewById(R.id.name_arguments);

转接器

package Fragments;

public interface sendArgument {
    void sendArgument (String Argument);
}

碎片

public class contrargument extends Fragment implements sendArgument {
    public String name_user_post_argument,argument_posted;
    TextView text_contrarguent,argument,valoration_argument;
    Button post_contrargument;
    ImageView increace_valoration,decreace_valoration,back_fragment;
    public int valoration;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
       View view = inflater.inflate(R.layout.fragment_contrargument, container, false);
       argument = view.findViewById(R.id.text_argument);
       text_contrarguent = view.findViewById(R.id.contrargument_post);
       post_contrargument = view.findViewById(R.id.post_contrargumment);
       name_user_post_argument = perfil_user.name_aux;
       increace_valoration = view.findViewById(R.id.increace_valoration);
       decreace_valoration = view.findViewById(R.id.decreace_valoration);
       valoration_argument = view.findViewById(R.id.valoration_argument);
       back_fragment = view.findViewById(R.id.returned);
       valoration = 0;

       increace_valoration.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                valoration = valoration + 1;
                valoration_argument.setText(String.valueOf(valoration));
            }
        });
        decreace_valoration.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(valoration > 0){
                    valoration =   valoration - 1;
                    valoration_argument.setText(String.valueOf(valoration));
                }
                else if (valoration == 0 ){
                    valoration_argument.setText(String.valueOf(0));
                }
                else{
                    //pass
                }
            }
        });

       return view;
    }

    @Override
    public void sendArgument(String Argument) {
        Toast.makeText(getActivity(), "Got: " + Argument, Toast.LENGTH_SHORT).show();
    }
}