I am new to android development and am trying to bind recycler View with setAdapter but am getting this error "Cannot resolve method 'setAdapter' in 'ConstraintLayout' "

my mainActivity.java code is:

my main objective is to use ActivityMainBinding to bind recyclerView with setAdapter

package com.example.baatcheet;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import com.example.baatcheet.usersAdapter.*;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import com.example.baatcheet.databinding.ActivityMainBinding;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

   ActivityMainBinding binding;
   FirebaseDatabase database;
   ArrayList<User> users;
   usersAdapter UserAdapter;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       binding = ActivityMainBinding.inflate(getLayoutInflater());
       
       setContentView(binding.getRoot());
       database = FirebaseDatabase.getInstance();
       users = new ArrayList<>();
       UserAdapter = new usersAdapter(this, users);
       binding.recyclerView.setAdapter(UserAdapter);



       database.getReference().child("users").addValueEventListener(new ValueEventListener() {
           @Override
           public void onDataChange(@NonNull DataSnapshot snapshot) {
               users.clear();
               for(DataSnapshot snapshot1 : snapshot.getChildren()){
                   User user = snapshot1.getValue(User.class);
                   users.add(user);
               }
               UserAdapter.notifyDataSetChanged();
           }

           @Override
           public void onCancelled(@NonNull DatabaseError error) {

           }
       });




   }

   @Override
   public boolean onOptionsItemSelected(@NonNull MenuItem item) {
       switch (item.getItemId()){
           case R.id.search:
               Toast.makeText(this,"Search Clicked" , Toast.LENGTH_SHORT).show();
               break;
           case R.id.settings:
               Toast.makeText(this , " setting Clicked" , Toast.LENGTH_SHORT).show();
               break;

       }
       return super.onOptionsItemSelected(item);
   }

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
       getMenuInflater().inflate(R.menu.top_menu,menu);
       return super.onCreateOptionsMenu(menu);
   }
}

this is the part where i am getting an error -> binding.recyclerView.setAdapter(UserAdapter);

and it tells me to rename reference what does this actually mean?

the activity_main.xml file is:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@ id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@ id/bottomNavigationView2"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:elevation="30dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:menu="@menu/menu">

    </com.google.android.material.bottomnavigation.BottomNavigationView>

    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@ id/bottomNavigationView2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:listitem="@layout/row_conversation"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

the users.java code is:

package com.example.baatcheet;

public class User {
    private String uid,name,phoneNumber,profileImage;
    public User(){

    }


    public User(String uid, String name, String phoneNumber, String profileImage) {
        this.uid = uid;
        this.name = name;
        this.phoneNumber = phoneNumber;
        this.profileImage = profileImage;
    }

    public void setUid(String uid) {
        this.uid = uid;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public void setProfileImage(String profileImage) {
        this.profileImage = profileImage;
    }

    public String getUid() {
        return uid;
    }

    public String getName() {
        return name;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public String getProfileImage() {
        return profileImage;
    }
}

the usersAdapter.java code is:

package com.example.baatcheet;

import android.content.Context;
import android.view.ContextMenu;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.example.baatcheet.databinding.RowConversationBinding;

import java.util.ArrayList;

public class usersAdapter extends RecyclerView.Adapter<usersAdapter.UsersViewHolder>{
    Context context;
    ArrayList<User> users;
    public  usersAdapter(Context context , ArrayList<User> users){
        this.context = context;
        this.users = users;
    }
    {

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

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

        User user = users.get(position);

        holder.binding.userName.setText(user.getName());
    }

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

    public class UsersViewHolder extends RecyclerView.ViewHolder{

        RowConversationBinding binding;
        public UsersViewHolder(@NonNull View itemView) {
            super(itemView);
            binding = RowConversationBinding.bind(itemView);
        }
    }
}

CodePudding user response：

In your layout file, it is the root ConstraintLayout that has the @ id/recyclerView id:

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@ id/recyclerView"
    ... />

You should move this id to the RecyclerView itself:

<androidx.recyclerview.widget.RecyclerView
    android:id="@ id/recyclerView"
    ... />

Once you do this, binding.recyclerView will refer to the RecyclerView instead of the ConstraintLayout.

If you need to access the ConstraintLayout via the view binding for some other reason, you can use binding.root.