linq结果集转换成datatable

    public static class Ext
    {
        public static DataTable ConvertToTable(this IEnumerable<ListEntity> obj)
        {
            if (obj == null) return null;
            var ret = new DataTable();
            ret.Columns.Add("id", typeof(ListEntity).GetField("id").FieldType);
            ret.Columns.Add("Fmsn", typeof(ListEntity).GetField("Fmsn").FieldType);
            ret.Columns.Add("State", typeof(ListEntity).GetField("State").FieldType);
            ret.Columns.Add("CardSerialNum", typeof(ListEntity).GetField("CardSerialNum").FieldType);
            ret.Columns.Add("CerGetDate", typeof(ListEntity).GetField("CerGetDate").FieldType);
            ret.Columns.Add("CerEndDate", typeof(ListEntity).GetField("CerEndDate").FieldType);
            ret.Columns.Add("OrgSn", typeof(ListEntity).GetField("OrgSn").FieldType);
            ret.Columns.Add("OrgCode", typeof(ListEntity).GetField("OrgCode").FieldType);
            ret.Columns.Add("OrgName", typeof(ListEntity).GetField("OrgName").FieldType);
            ret.Columns.Add("FmName", typeof(ListEntity).GetField("FmName").FieldType);
            foreach (var item in obj)
            {
                DataRow r = ret.NewRow();
                r["id"] = item.id;
                r["Fmsn"] = item.Fmsn;
                r["State"] = item.State;
                r["CardSerialNum"] = item.CardSerialNum;
                r["CerGetDate"] = item.CerGetDate;
                r["CerEndDate"] = item.CerEndDate;
                r["OrgSn"] = item.OrgSn;
                r["OrgCode"] = item.OrgCode;
                r["OrgName"] = item.OrgName;
                r["FmName"] = item.FmName;
                ret.Rows.Add(r);
            }
            return ret;
        }
    }

[Serializable]
    [DataContract]
    public class ListEntity
    {
        [DataMember]
        public int id { get; set; }

        [DataMember]
        public string Fmsn { get; set; }

        [DataMember]
        public int State { get; set; }

        [DataMember]
        public string CardSerialNum { get; set; }

        [DataMember]
        public System.Nullable<System.DateTime> CerGetDate { get; set; }

        [DataMember]
        public System.Nullable<System.DateTime> CerEndDate { get; set; }

        [DataMember]
        public string OrgSn { get; set; }

        [DataMember]
        public string OrgCode { get; set; }

        [DataMember]
        public string OrgName { get; set; }

        [DataMember]
        public string FmName { get; set; }
    }