生成订单号

//生成订单号
    public string GetOrderNO()
    {
        StringBuilder result = new StringBuilder();
        DateTime now = DateTime.Now;
        result.Append(now.Year.ToString().Substring(2, 2));
        string month = now.Month.ToString();
        result.Append(month.Length < 2 ? "0" + month : month);
        string day = now.Day.ToString();
        result.Append(day.Length < 2 ? "0" + day : day);
        String hour = now.Hour.ToString();
        result.Append(hour.Length < 2 ? "0" + hour : hour);
        string minute = now.Minute.ToString();
        result.Append(minute.Length < 2 ? "0" + minute : minute);
        string second = now.Second.ToString();
        result.Append(second.Length < 2 ? "0" + second : second);
        int last = new Random().Next(10000);
        result = result.Append(last.ToString());
        if (last > 99 && last <= 999)
        {
            result = result.Append("0");
        }
        else if (last > 9 && last <= 99)
        {
            result = result.Append("00");
        }
        else if (last <= 9)
        {
            result = result.Append("000");
        }
        else
        {

        }
        return result.ToString();
    }