Android工作室暂停和恢复倒计时计时器的进度条

Question

我正在使用一个倒计时计时器，它更新我的进度条，从100(满)减少到0(空)，但当应用程序暂停时，我想暂停计时器，然后在恢复应用程序时重新启动它。我实现倒计时计时器如下:

public class MyCountDownTimer extends CountDownTimer {

    public MyCountDownTimer(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);
    }
    @Override
    public void onTick(long millisUntilFinished) {
        int progress = (int) (millisUntilFinished / 100);
        progressBar.setProgress(progress);
    }
    @Override
    public void onFinish() {
        progressBar.setProgress(0);
        Intent intent = new Intent(getApplicationContext(), GameOver.class);
        startActivity(intent);
        finish();
    }
}

And in my on create:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_play_screen);
    progressBar = (ProgressBar)findViewById(R.id.timerBar);
    progressBar.setProgress(100);
    myCountDownTimer = new MyCountDownTimer(10000, 10);
    myCountDownTimer.start();
}

Answer 1

你可以在你的MyCountDownTimer类中添加一个布尔值，它将在你的Activity的onPause和onResume方法中改变。检查// ADDED注释，看看你必须做出的改变，使这项工作。

public class MyActivity extends Activity {
    MyCountDownTimer myCountDownTimer;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_play_screen);
        progressBar = (ProgressBar)findViewById(R.id.timerBar);
        progressBar.setProgress(100);
        myCountDownTimer = new MyCountDownTimer(10000, 10);
        myCountDownTimer.start();
    }
   // ADDED
   @Override
   public void onPause() {
       super.onPause();  // Always call the superclass method first
       myCountDownTimer.pause();
   }
   // ADDED
   @Override
   public void onResume() {
       super.onResume();  // Always call the superclass method first
       myCountDownTimer.resume();
   }
}

public class MyCountDownTimer extends CountDownTimer {
    // ADDED
    private boolean pause;
    public MyCountDownTimer(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);
    }
    // ADDED
    public void pause() {
        pause = true;
    }
    // ADDED
    public void resume() {
        pause = false;
    }
    @Override
    public void onTick(long millisUntilFinished) {
        int progress = (int) (millisUntilFinished / 100);
        // ADDED
        if (!pause) {
            progressBar.setProgress(progress);
        }
    }
    @Override
    public void onFinish() {
        // ADDED
        isRunning = false;
        progressBar.setProgress(0);
        Intent intent = new Intent(getApplicationContext(), GameOver.class);
        startActivity(intent);
        finish();
    }
}