Chronometer 計時器結合LifeCycle使用

對系統的Chronometer進行簡單的封裝

public class MyChronometer extends Chronometer implements LifecycleObserver {

    private long elapsedTime;

    public MyChronometer(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    private void pauseMeter(){
        elapsedTime = SystemClock.elapsedRealtime() - getBase();
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    private void resumeMeter(){
        setBase(SystemClock.elapsedRealtime() - elapsedTime);
        start();
    }
}

然後在XML中註冊

在Activity中使用，並註冊監聽

MyChronometer chronometer = findViewById(R.id.meter);
getLifecycle().addObserver(chronometer);