[Android] ListView 만들고 adapter로 연결하기 - Java

android ListView

 

package com.example.listexample01;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private ListView list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        list = (ListView) findViewById(R.id.list);
        List<String> data = new ArrayList<>();

        ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, data);
        list.setAdapter(adapter);

        data.add("LMJ");
        data.add("Fighting!");
        data.add("Fighting!");
        adapter.notifyDataSetChanged();

    }
}

 

<?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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ListView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </ListView>

</LinearLayout>

 

ArrayList 와 실제 레이아웃의 ListView를 연결해주기 위해서는

다음과 같이 adapter를 이용하여 둘을 연결해주어야 한다.

        list = (ListView) findViewById(R.id.list);
        List<String> data = new ArrayList<>();

        ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, data);
        list.setAdapter(adapter);

        data.add("LMJ");
        data.add("Fighting!");
        data.add("Fighting!");
        adapter.notifyDataSetChanged();