MainActivity.java

package com.testappu.todolistapplicationmlh;

import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;

import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.EditText;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
    private ArrayList <String> items;
    private ArrayAdapter<String> itemsAdapter;
    private ListView lvItems;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lvItems = (ListView) findViewById(R.id.lvItems);
        items = new ArrayList<String>();
        itemsAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, items);
        lvItems.setAdapter(itemsAdapter);
        items.add("First Item");
        items.add("Second Item");
    }

    public void onAddItem(View v) {
        EditText etNewItem = (EditText) findViewById(R.id.etNewItem);
        String itemText = etNewItem.getText().toString();
        itemsAdapter.add(itemText);
        etNewItem.setText("");
    }
}