从WCF服务返回的Json数据不完整

我从一个NET类返回JSON与我的WCF服务的4个属性。问题是当它被发送到浏览器(IE, Chrome, FF)。它只返回类

中的一个属性

。NET类:

[DataContract]
    public class MASInspections
    {
        [DataMember]
        public int MaintID { get; set; }
        public string MHID { get; set; }
        public DateTime MaintDate { get; set; }
        public string pdfReport { get; set; }
    }

。网络接口:

[OperationContract]
    [WebInvoke(Method = "GET",
        ResponseFormat = WebMessageFormat.Json,
        BodyStyle = WebMessageBodyStyle.Wrapped,
        UriTemplate = "GetInspectionByReach/{Reach}")]
    List<MASInspections> GetInspectionByReach(string Reach);

。净方法:

 public List<MASInspections> GetInspectionByReach(string Reach)
    {
        List<MASInspections> InspInfos = new List<MASInspections>();
        DataSet ds = DBCalls.GetInspectionByReach(Reach);
        DataTable dt = ds.Tables[0];
        DataRowCollection drc = dt.Rows;
        for (int i = 0; i < drc.Count; i++)
        {
            object[] values = drc[i].ItemArray;
            MASInspections InspInfo = new MASInspections();
            InspInfo.MaintID = Convert.ToInt32(values[0]);
            InspInfo.MHID = Convert.ToString(values[1]);
            InspInfo.MaintDate = Convert.ToDateTime(values[5]);
            InspInfo.pdfReport = Convert.ToString(values[6]);
            InspInfos.Add(InspInfo);
        }
        return InspInfos;//this inlcudes all 4 properties
    }

当json被发送到浏览器时，只有MaintID在那里:

    {"GetInspectionByReachResult":[{"MaintID":133},{"MaintID":178}]}

知道为什么会这样吗?

谢谢

[DataContract]
    public class MASInspections
    {
        [DataMember]
        public int MaintID { get; set; }
        public string MHID { get; set; }
        public DateTime MaintDate { get; set; }
        public string pdfReport { get; set; }
    }

[DataContract]
    public class MASInspections
    {
        [DataMember]
        public int MaintID { get; set; }
        [DataMember]
        public string MHID { get; set; }
        [DataMember]
        public DateTime MaintDate { get; set; }
        [DataMember]
        public string pdfReport { get; set; }
    }