恢复Android倒计时计时器

public class MainActivity extends AppCompatActivity {
    private CountDownTimer countDownTimer;
    private long timeLeftInMillis;
    private boolean isTimerRunning;

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

        // 初始化倒计时时间和状态
        timeLeftInMillis = 60000; // 60秒
        isTimerRunning = false;

        // 创建倒计时计时器
        countDownTimer = new CountDownTimer(timeLeftInMillis, 1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                timeLeftInMillis = millisUntilFinished;
                updateCountdownText();
            }

            @Override
            public void onFinish() {
                isTimerRunning = false;
                // 倒计时结束时的操作
                // ...
            }
        };

        // 恢复倒计时计时器状态
        if (savedInstanceState != null) {
            timeLeftInMillis = savedInstanceState.getLong("timeLeftInMillis");
            isTimerRunning = savedInstanceState.getBoolean("isTimerRunning");

            if (isTimerRunning) {
                startTimer();
            }
        }

        // 开始或暂停倒计时计时器
        Button startButton = findViewById(R.id.start_button);
        startButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (isTimerRunning) {
                    pauseTimer();
                } else {
                    startTimer();
                }
            }
        });
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putLong("timeLeftInMillis", timeLeftInMillis);
        outState.putBoolean("isTimerRunning", isTimerRunning);
    }

    private void startTimer() {
        countDownTimer.start();
        isTimerRunning = true;
        // 更新按钮文本等UI操作
        // ...
    }

    private void pauseTimer() {
        countDownTimer.cancel();
        isTimerRunning = false;
        // 更新按钮文本等UI操作
        // ...
    }

    private void updateCountdownText() {
        // 更新倒计时文本显示
        // ...
    }
}