如何处理负计时器倒计时ListView中的负计时器？

Question

如何处理负计时器倒计时ListView中的负计时器

public class MainActivity extends AppCompatActivity {

private ListView lvItems;
private List<Product> lstProducts;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    lvItems = (ListView) findViewById(R.id.lvItems);
    lstProducts = new ArrayList<>();
    lstProducts.add(new Product("A", System.currentTimeMillis() + 10000));
    lstProducts.add(new Product("B", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("C", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("D", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("E", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("F", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("G", System.currentTimeMillis() + 30000));
    lstProducts.add(new Product("H", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("I", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("J", System.currentTimeMillis() + 40000));
    lstProducts.add(new Product("K", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("L", System.currentTimeMillis() + 50000));
    lstProducts.add(new Product("M", System.currentTimeMillis() + 60000));
    lstProducts.add(new Product("N", System.currentTimeMillis() + 20000));
    lstProducts.add(new Product("O", System.currentTimeMillis() + 10000));

    lvItems.setAdapter(new CountdownAdapter(MainActivity.this, lstProducts));

}

private class Product {
    String name;
    long expirationTime;

    public Product(String name, long expirationTime) {
        this.name = name;
        this.expirationTime = expirationTime;
    }
}

public class CountdownAdapter extends ArrayAdapter<Product> {

    private LayoutInflater lf;
    private List<ViewHolder> lstHolders;
    private Handler mHandler = new Handler();
    private Runnable updateRemainingTimeRunnable = new Runnable() {
        @Override
        public void run() {
            synchronized (lstHolders) {
                long currentTime = System.currentTimeMillis();
                for (ViewHolder holder : lstHolders) {
                    holder.updateTimeRemaining(currentTime);
                }
            }
        }
    };

    public CountdownAdapter(Context context, List<Product> objects) {
        super(context, 0, objects);
        lf = LayoutInflater.from(context);
        lstHolders = new ArrayList<>();
        startUpdateTimer();
    }

    private void startUpdateTimer() {
        Timer tmr = new Timer();
        tmr.schedule(new TimerTask() {
            @Override
            public void run() {
                mHandler.post(updateRemainingTimeRunnable);
            }
        }, 1000, 1000);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = lf.inflate(R.layout.list_item, parent, false);
            holder.tvProduct = (TextView) convertView.findViewById(R.id.tvProduct);
            holder.tvTimeRemaining = (TextView) convertView.findViewById(R.id.tvTimeRemaining);
            convertView.setTag(holder);
            synchronized (lstHolders) {
                lstHolders.add(holder);
            }
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.setData(getItem(position));

        return convertView;
    }
}

private class ViewHolder {
    TextView tvProduct;
    TextView tvTimeRemaining;
    Product mProduct;

    public void setData(Product item) {
        mProduct = item;
        tvProduct.setText(item.name);
        updateTimeRemaining(System.currentTimeMillis());
    }

    public void updateTimeRemaining(long currentTime) {
        long timeDiff = mProduct.expirationTime - currentTime;
        if (timeDiff > 0) {
            int seconds = (int) (timeDiff / 1000) % 60;
            int minutes = (int) ((timeDiff / (1000 * 60)) % 60);
            int hours = (int) ((timeDiff / (1000 * 60 * 60)) % 24);
            tvTimeRemaining.setText(hours + " hrs " + minutes + " mins " + seconds + " sec");
        } else {
            tvTimeRemaining.setText("Expired!!");
        }
    }
}

}

这是我在这里的主要活动当我完成时，我应该如何以负面开始计时。我有两个textview的listview