CountDownTimer onTick()无法更新类的成员

public class MyCountDownTimer {
    private long mRemainingTime; // 类的成员变量
    private long mCountDownInterval;
    private CountDownTimer mCountDownTimer;

    public void startCountDown(long millisInFuture, long countDownInterval) {
        mRemainingTime = millisInFuture;
        mCountDownInterval = countDownInterval;

        mCountDownTimer = new CountDownTimer(millisInFuture, countDownInterval) {
            @Override
            public void onTick(long millisUntilFinished) {
                mRemainingTime = millisUntilFinished; // 更新中间变量
                // 在这里执行其他操作
            }

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

        mCountDownTimer.start();
    }

    public long getRemainingTime() {
        return mRemainingTime; // 返回中间变量的值
    }
}