RecyclerView in Android – a Simple Example

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rycViewSubject"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rycViewSubject"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

package vn.edu.ntu.vidurecycleview_simpletext;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

import java.util.List;

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.MyItemViewHolder>{
    private List<String> mSubjectList;
    private LayoutInflater mInflater;

    public MyRecyclerViewAdapter(Context mContext,List<String> mSubjectList) {
        this.mSubjectList = mSubjectList;
        this.mInflater = LayoutInflater. from(mContext);
    }

    @NonNull
    @Override
    public MyItemViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.recyclerview_row_item, parent, false);
        return new MyItemViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyItemViewHolder holder, int position) {
        String subject = mSubjectList.get(position);
        holder.myTextView_SubjectName.setText(subject);
    }

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

    class  MyItemViewHolder extends RecyclerView.ViewHolder {
        TextView myTextView_SubjectName;
        MyItemViewHolder (View view) {
            super(view);
            myTextView_SubjectName = view.findViewById(R.id.tvSubjectName);
        }
    }
}

package vn.edu.ntu.vidurecycleview_simpletext;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    MyRecyclerViewAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // data to populate the RecyclerView with
        ArrayList<String> subjectNames = new ArrayList<>();
        subjectNames.add("Maths");
        subjectNames.add("Physics");
        subjectNames.add("Economics");
        subjectNames.add("C Programming");
        subjectNames.add("Java Progamming");
        // set up the RecyclerView
        RecyclerView recyclerView = findViewById(R.id.rycViewSubject);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        adapter = new MyRecyclerViewAdapter(subjectNames);
        recyclerView.setAdapter(adapter);
    }
}