[ 안드로이드 기본 ] 간단한 Handler 테스트

1. HandlerTest

Handler 를 활용해 다음과 같은 화면 만들어보기

▼결과화면

▼actuvity_main.xml 코드

<?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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="236dp"
        android:layout_weight="1"
        android:gravity="center"
        android:text="Remove The Bomb"
        android:textSize="34sp" />

    <ProgressBar
        android:id="@+id/progressBar"
        style="@style/Widget.AppCompat.ProgressBar.Horizontal"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:layout_weight="1"
        android:max="100"
        android:progress="100" />

</LinearLayout>

▼MainActivity.java 코드

package kr.ac.dju.handlertest;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ProgressBar;

import androidx.activity.EdgeToEdge;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {

    private ProgressBar progressBar;
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            if(progressBar.getProgress()>0) {
                progressBar.setProgress(progressBar.getProgress()-1);
            }
            handler.sendEmptyMessageDelayed(WHAT_PROGRESS, DELAY_MS);
        }
    };

    public static final long DELAY_MS = 100;
    public static final int WHAT_PROGRESS = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        progressBar= (ProgressBar)findViewById(R.id.progressBar);
        handler.sendEmptyMessageDelayed(WHAT_PROGRESS, DELAY_MS);
    }
}