android - 无法在 recyclerview 适配器类中解析

Question

这是我的适配器类代码 -

package com.referral.abhin.myapplication;

import android.app.Activity;
import android.content.ClipData;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.Typeface;
import android.preference.Preference;
import android.provider.ContactsContract;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.widget.PopupMenu;
import android.support.v7.widget.RecyclerView;
import android.text.method.SingleLineTransformationMethod;
import android.util.Base64;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.Map;

import static android.content.Context.MODE_PRIVATE;
import static android.view.View.GONE;

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

    List<post> objPost;

    private FirebaseDatabase mFirebaseDatabaseCheck;
    private DatabaseReference mMessagesDatabaseReferenceCheck;
    private DatabaseReference mMessagesDatabaseReference_notification;

    private FirebaseDatabase mFirebaseDatabaseComment;
    private DatabaseReference mMessagesDatabaseReferenceComment;

    private FirebaseDatabase mFirebaseDatabaseLikes;
    private DatabaseReference mMessagesDatabaseReferenceLikes;

    //Constructor - Get data passed in local list
    public postAdapter(List<post> objectPost) {
        objPost = objectPost;
    }

    //Inititalizing Shared Preference
    SharedPreferences sharedPreferences;
    private static final String SHARED_PREF = "sharedPref";


//    @Override
//    public post getItem(int position) {
//        return super.getItem(getCount() - position - 1);
//    }

//    private final View.OnClickListener mOnClickListener = new MyOnClickListener();

//    @Override
//    public class ViewHolder extends RecyclerView.ViewHolder{
//
//        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
//        View view = inflater.inflate(R.layout.itemsinpost, parent, false);
//        view.setOnClickListener(mOnClickListener);
//        return new postViewHolder(view);
//
//        public ViewHolder(View itemView) {
//            super(itemView);
//        }
//    }


    //nested class with holder
    public class postViewHolder extends RecyclerView.ViewHolder{

        TextView companyObj;
        TextView locationObj;
        TextView categoryObj;
        TextView salaryObj;
        TextView dateView;
        LinearLayout itemsInRecyclerView;

        public postViewHolder(View listItemView){
            super(listItemView);
            companyObj = listItemView.findViewById(R.id.company);
            locationObj = listItemView.findViewById(R.id.location);
            categoryObj = listItemView.findViewById(R.id.category);
            salaryObj = listItemView.findViewById(R.id.salary);
            dateView = listItemView.findViewById(R.id.dateTime);
            itemsInRecyclerView = listItemView.findViewById(R.id.listViewLayout);
        }
    }

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

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        final post objectFile = objPost.get(position);

        //Firebase to update Like, Report value and also get called on delete button
        mFirebaseDatabaseLikes = FirebaseDatabase.getInstance();
        mMessagesDatabaseReferenceLikes = mFirebaseDatabaseLikes.getReference().child("counter");

        //Firebase reference called only to update number of comments
        mFirebaseDatabaseComment = FirebaseDatabase.getInstance();
        mMessagesDatabaseReferenceComment = mFirebaseDatabaseComment.getReference().child("comments");

        //Firebase reference to check if the user has already liked the post or not
        mFirebaseDatabaseCheck = FirebaseDatabase.getInstance();
        mMessagesDatabaseReferenceCheck = mFirebaseDatabaseCheck.getReference().child("check_counter");

        //segregate email to userID
        String[] emailSegregate = sharedPreferences.getString("email", "anonymous").split("@");
        String emailID = emailSegregate[0];

        mMessagesDatabaseReference_notification = mFirebaseDatabaseCheck
                .getReference()
                .child("notification_list")
                .child(emailID)
                .child(objectFile.getnodeId());

        if (objectFile.getType().equals("post"))

        {
            holder.companyObj.setText(objectFile.getCompany());
            holder.companyObj.setVisibility(View.VISIBLE);

            holder.locationObj.setText("Location : " + objectFile.getLocation());
            holder.locationObj.setVisibility(View.VISIBLE);

            holder.categoryObj.setText(objectFile.getField());
            holder.categoryObj.setVisibility(View.VISIBLE);

            //if package is not empty
            if(!objectFile.getminPack().isEmpty() && !objectFile.getminPack().equals("0")) {
                //if work exp is not empty
                if (!objectFile.getworkExp().isEmpty()) {
                    holder.salaryObj.setText("₹ " + objectFile.getminPack() + " LPA, " + objectFile.getworkExp() + "+ Years of Work Exp.");
                }
                //if work exp is empty
                else {
                    holder.salaryObj.setText("₹ " + objectFile.getminPack() + " LPA, " + " Freshers Allowed");
                }
            }
            //if package is empty
            else{
                //if work exp is not empty
                if (!objectFile.getworkExp().isEmpty()) {
                    holder.salaryObj.setText(objectFile.getworkExp() + "+ Years of Work Exp.");
                }
                //if work exp is empty
                else {
                    holder.salaryObj.setText("Freshers Allowed");
                }
            }
            holder.salaryObj.setVisibility(View.VISIBLE);

        } else

        {

            holder.companyObj.setText("");
            holder.companyObj.setVisibility(GONE);

            holder.salaryObj.setText("");
            holder.salaryObj.setVisibility(GONE);

            holder.locationObj.setText("");
            holder.locationObj.setVisibility(GONE);

            holder.categoryObj.setText(objectFile.getPost());
            holder.categoryObj.setVisibility(View.VISIBLE);
        }

//        TextView usernameObj = listItemView.findViewById(R.id.username);
//        usernameObj.setText(objectFile.getName()); //displays name while username is email address saved in database


        final String[] data = objectFile.getDate().split(" ");
        String dateReceived = data[0];
        String timeReceived = data[1] + " " + data[2];

        String[] dateSegregate = dateReceived.split("/");
        int d = Integer.parseInt(dateSegregate[0]);
        int m = Integer.parseInt(dateSegregate[1]);
        int y = Integer.parseInt(dateSegregate[2]);

        Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH) + 1;
        int date = c.get(Calendar.DATE);

        if (date == d && month == m && year == y)

        {
            holder.dateView.setText(timeReceived);
        } else if (d == (date - 1) && month == m && year == y)

        {
            holder.dateView.setText("Yesterday");
        } else

        {
            holder.dateView.setText(dateReceived);
        }

    }

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

这是错误 -

如何解决？我已经根据 this 添加了代码工作正常的教程。

当我已经声明了 View Holder 时，为什么它没有获取 companyObj？

Answer 1

将这一行改成这样

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

到

public class postAdapter extends RecyclerView.Adapter<postAdapter. postViewHolder>{

然后更新这段代码

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

@Override
public void onBindViewHolder(@NonNull postAdapter.postViewHolder holder, int position) {

希望这能帮助解决您的问题。