[Android] Timer 구현 - Handler

 

 

 

- Timer 시작 버튼을 누르면 카운팅

- 일시정지 버튼을 통해서 타이머 일시정지

- 시작 버튼을 다시 누르면 멈췄던 숫자에서 재 카운팅

 

 

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Layout 디자인

 

 

Log 기록

 

 

[MainActivity.java]

public class MainActivity extends AppCompatActivity {

    private static final int MESSAGE_TIMER1_START = 100;
    
    TimerHandler timerHandler = null;

    Button buttonStart, buttonStop;

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

        timerHandler = new TimerHandler();

        buttonStart = findViewById(R.id.buttonStart);
        buttonStop = findViewById(R.id.buttonStop);

        buttonStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                timerHandler.sendEmptyMessage(MESSAGE_TIMER1_START);
            }
        });
        buttonStop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                timerHandler.removeMessages(MESSAGE_TIMER1_START);
            }
        });
    }

    private class TimerHandler extends Handler {
        int count = 0;

        @Override
        public void handleMessage(Message msg) {
            switch(msg.what) {
                case MESSAGE_TIMER1_START:
                    Log.d("TimerHandler", "Timer Start : " + count++);
                    this.sendEmptyMessageDelayed(MESSAGE_TIMER1_START, 1000);
                    break;
            }
        }
    }
}

 

 

[activity_main.xml]

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/buttonStart"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="타이머 시작"
        app:layout_constraintBottom_toTopOf="@+id/buttonStop"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.866" />

    <Button
        android:id="@+id/buttonStop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="312dp"
        android:text="타이머 멈춤(일시정지)"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent" />
</android.support.constraint.ConstraintLayout>