使用DataSet XML不返回null值

Question

这是DataSet XML，我试图提取代码，值，描述的值，但是获取null：

<DataSet xmlns="http://tempuri.org/">
<xs:schema xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" id="NewDataSet">
<xs:element name="response">
<xs:complexType>
<xs:sequence>
<xs:element name="user" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="id" type="xs:string"/>
</xs:complexType>
</xs:element>
<xs:element name="status" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="code" type="xs:string"/>
<xs:attribute name="value" type="xs:string"/>
<xs:attribute name="description" type="xs:string"/>
</xs:complexType>
</xs:element>
<xs:element name="error" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="code" type="xs:string"/>
<xs:attribute name="message" type="xs:string"/>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="operation" type="xs:string"/>
<xs:attribute name="timestamp" type="xs:string"/>
</xs:complexType>
</xs:element>
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element ref="response"/>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
<NewDataSet xmlns="">
<response diffgr:id="response1" msdata:rowOrder="0" diffgr:hasChanges="inserted" operation="AUTHENTICATION" timestamp="2015-11-19 20:54:16.172" msdata:hiddenresponse_Id="0">
<user diffgr:id="user1" msdata:rowOrder="0" diffgr:hasChanges="inserted" id="blumaesnetwork" msdata:hiddenresponse_Id="0"/>
<status diffgr:id="status1" msdata:rowOrder="0" diffgr:hasChanges="inserted" code="315" value="FAILED" description="Authentication Failed. User ID Not Found" msdata:hiddenresponse_Id="0"/>
<error diffgr:id="error1" msdata:rowOrder="0" diffgr:hasChanges="inserted" code="-1" message="User Not Found" msdata:hiddenresponse_Id="0"/>
</response>
</NewDataSet>
</diffgr:diffgram>
</DataSet>

以下是我的消费代码;请问我做错了什么：

var dbcServ = new DBConnectSoapClient("DBConnectSoap121");
DataSet ds = dbcServ.ValidateOnlineToken(_wsHeader, InternetBankingID, Token);
ds.Locale = CultureInfo.InvariantCulture;
               FillDataSet(ds);

               DataTable status = ds.Tables["status"];

               IEnumerable<DataRow> query =
                   from code in status.AsEnumerable()
                   select code;

               Console.WriteLine("diffgr:id code:");
               foreach (DataRow p in query)
               {
                   Console.WriteLine(p.Field<string>("code"));
               }


                if (codeField == "300")
                {    
                    return true;
                }
                else
                {
                    return false;
                }
            }

以上是我的消费代码;请问我做错了什么（尝试提取代码，值，描述的值但是为空）