public static Traderate ToObject(string str)
    {
        if (str == null || str.Equals(String.Empty))
        {
            return(null);
        }
        JsonData jd = JsonMapper.ToObject(str);

        return(new Traderate((int)jd[Param.TID], (long)jd[Param.NUM_IID],
                             Traderate.StringToROLE((string)jd[Param.ROLE]), (string)jd[Param.NICK],
                             Traderate.StringToRateResult((string)jd[Param.RESULT]),
                             StringUtil.StringToDateTime((string)jd[Param.CREATED]),
                             (string)jd[Param.CONTENT], (string)jd[Param.REPLY]));
    }
    public static List <Traderate> ToObjects(string str)
    {
        if (str == null || str.Equals(String.Empty))
        {
            return(null);
        }
        JsonData jd = JsonMapper.ToObject(str);

        if (!jd.IsArray)
        {
            return(null);
        }
        List <Traderate> list = new List <Traderate>();

        for (int i = 0; i < jd.Count; ++i)
        {
            Traderate traderate = ToObject(jd[i].ToJson());
            if (traderate != null)
            {
                list.Add(traderate);
            }
        }
        return(list);
    }