WCF Web Service serialization error - returning null values

Question

My Problem:

I have a WCF Web Service that is being called by a simple .NET test client and is returning null values for several of the properties of the custom class that is being being returned.

• Checking the values of the return object at a breakpoint just before it is returned shows me that all of the values are correctly populated, but the value of that object as soon as it is received shows several of its properties as being 'null.'
• I have read several other stackoverflow posts of people reporting the same issue, and several have been resolved by alphabetizing / assigning an order to the [DataContracts] in the interface, but that has not affected my results.
• The values seem to be reaching the client program though, because the response from running a SoapUI test shows the correct values in the XML.

Code:

[ServiceContract]
public interface IService
{
    [OperationContract]
    TotalTaxResult GetTotalTax(OrderHeader orderHeader);
}

[DataContract]
public class TotalTaxResult
{
    [DataMember]
    public string Message { get; set; }

    [DataMember]
    public ProductLineItem[] ProductLineItems { get; set; }

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

    [DataMember]
    public DataSet ResultDataSet { get; set; }

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

    [DataMember]
    public DataSet taxDataSet { get; set; }

    [DataMember(IsRequired = true)]
    public decimal TotalTax { get; set; }

    [DataMember]
    public Avalara.AvaTax.Adapter.TaxService.TaxLines TotalTaxLines { get; set; }

}

Soap Request

     <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/" xmlns:sal="http://schemas.datacontract.org/2004/07/SalesService">
   <soapenv:Header/>
   <soapenv:Body>
      <tem:GetTotalTax>
         <!--Optional:-->
         <tem:orderHeader>
            <!--Optional:-->
            <sal:BFCustomerNumber>123456</sal:BFCustomerNumber>
            <!--Optional:-->
            <sal:BFStoreNumber>654321</sal:BFStoreNumber>
            <!--Optional:-->
            <sal:CustomerName>Nick T</sal:CustomerName>
            <!--Optional:-->
            <sal:Message></sal:Message>
            <sal:OrderLineItems>
               <!--Zero or more repetitions:-->
               <sal:OrderLineItem>
                  <sal:ItemNumber>164080</sal:ItemNumber>
                  <sal:LineNumber>1</sal:LineNumber>
                  <sal:Price>100</sal:Price>
                  <sal:Quantity>1</sal:Quantity>
                  <sal:TaxCode>S</sal:TaxCode>
                  <sal:UoM>CA</sal:UoM>
               </sal:OrderLineItem>
            </sal:OrderLineItems>
            <!--Optional:-->
            <sal:PONumber>333000</sal:PONumber>
            <!--Optional:-->
            <sal:ResultCode></sal:ResultCode>
            <!--Optional:-->
            <sal:SourceSystem>WEB</sal:SourceSystem>
            <sal:TestFlag>true</sal:TestFlag>
            <!--Optional:-->
            <sal:TotalTax></sal:TotalTax>
            <!--Optional:-->
            <sal:WarehouseNum>3010</sal:WarehouseNum>
            <!--Optional:-->
            <sal:validDest>
               <!--Optional:-->
               <sal:AddressCode></sal:AddressCode>
               <!--Optional:-->
               <sal:AddressType>S</sal:AddressType>
               <!--Optional:-->
               <sal:CarrierRoute>C022</sal:CarrierRoute>
               <!--Optional:-->
               <sal:City>SAINT LOUIS</sal:City>
               <!--Optional:-->
               <sal:Country>US</sal:Country>
               <!--Optional:-->
               <sal:County>SAINT LOUIS</sal:County>
               <!--Optional:-->
               <sal:FipsCode>2918900000</sal:FipsCode>
               <!--Optional:-->
               <sal:Latitude>30.0000</sal:Latitude>
               <!--Optional:-->
               <sal:Line1>1234 DELMAR DR</sal:Line1>
               <!--Optional:-->
               <sal:Line2></sal:Line2>
               <!--Optional:-->
               <sal:Line3></sal:Line3>
               <!--Optional:-->
               <sal:Line4>SAINT LOUIS MO 63130-6642</sal:Line4>
               <!--Optional:-->
               <sal:Longitude>-95.8765</sal:Longitude>
               <!--Optional:-->
               <sal:PostNet>631306632524</sal:PostNet>
               <!--Optional:-->
               <sal:PostalCode>63130-6642</sal:PostalCode>
               <!--Optional:-->
               <sal:Region>MO</sal:Region>
            </sal:validDest>
            <!--Optional:-->
            <sal:validOrigin>
               <!--Optional:-->
               <sal:AddressCode></sal:AddressCode>
               <!--Optional:-->
               <sal:AddressType>H</sal:AddressType>
               <!--Optional:-->
               <sal:CarrierRoute>R030</sal:CarrierRoute>
               <!--Optional:-->
               <sal:City>SAINT CHARLES</sal:City>
               <!--Optional:-->
               <sal:Country>US</sal:Country>
               <!--Optional:-->
               <sal:County>SAINT CHARLES</sal:County>
               <!--Optional:-->
               <sal:FipsCode>296543210</sal:FipsCode>
               <!--Optional:-->
               <sal:Latitude>35.8034</sal:Latitude>
               <!--Optional:-->
               <sal:Line1>500 ORCHARD LAKES BLVD</sal:Line1>
               <!--Optional:-->
               <sal:Line2></sal:Line2>
               <!--Optional:-->
               <sal:Line3></sal:Line3>
               <!--Optional:-->
               <sal:Line4>SAINT CHARLES MO 63331-4341</sal:Line4>
               <!--Optional:-->
               <sal:Longitude>-95.5021</sal:Longitude>
               <!--Optional:-->
               <sal:PostNet>63389541997</sal:PostNet>
               <!--Optional:-->
               <sal:PostalCode>63331-4341</sal:PostalCode>
               <!--Optional:-->
               <sal:Region>MO</sal:Region>
            </sal:validOrigin>
         </tem:orderHeader>
      </tem:GetTotalTax>
   </soapenv:Body>
</soapenv:Envelope>

Soap Response:

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Body>
      <GetTotalTaxResponse xmlns="http://tempuri.org/">
         <GetTotalTaxResult xmlns:a="http://schemas.datacontract.org/2004/07/SalesService" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
            <a:Message>Total Tax Calc</a:Message>
            <a:ProductLineItems i:nil="true"/>
            <a:ResultCode>7.46</a:ResultCode>
            <a:ResultDataSet i:nil="true"/>
            <a:TotalTax>7.46</a:TotalTax>
            <a:TotalTaxLines xmlns:b="http://schemas.datacontract.org/2004/07/Avalara.AvaTax.Adapter.TaxService"/>
            <a:strTaxLinesCount>1</a:strTaxLinesCount>
            <a:taxDataSet>
               <xs:schema id="NewDataSet" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
                  <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
                     <xs:complexType>
                        <xs:choice minOccurs="0" maxOccurs="unbounded">
                           <xs:element name="TaxDataTable">
                              <xs:complexType>
                                 <xs:sequence>
                                    <xs:element name="TaxIndex" type="xs:int" minOccurs="0"/>
                                    <xs:element name="TaxLineNo" type="xs:string" minOccurs="0"/>
                                    <xs:element name="TaxCode" type="xs:string" minOccurs="0"/>
                                    <xs:element name="TaxAmount" type="xs:decimal" minOccurs="0"/>
                                 </xs:sequence>
                              </xs:complexType>
                           </xs:element>
                        </xs:choice>
                     </xs:complexType>
                  </xs:element>
               </xs:schema>
               <diffgr:diffgram xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
                  <NewDataSet xmlns="">
                     <TaxDataTable diffgr:id="TaxDataTable1" msdata:rowOrder="0" diffgr:hasChanges="inserted">
                        <TaxIndex>0</TaxIndex>
                        <TaxLineNo>1</TaxLineNo>
                        <TaxCode>P0000000</TaxCode>
                        <TaxAmount>7.46</TaxAmount>
                     </TaxDataTable>
                  </NewDataSet>
               </diffgr:diffgram>
            </a:taxDataSet>
         </GetTotalTaxResult>
      </GetTotalTaxResponse>
   </s:Body>
</s:Envelope>

.NET Client Results:

'null' values for:

• ProductLineItems
• strTaxLinesCount
• ResultDataSet returns as an empty DataSet
• taxDataSet
• TotalTax returns as '0'
• TotalTaxLines

The only properties with their proper values are:

• Message
• ResultCode

No exceptions are thrown during the entire process.

Ordering the interface through [DataMember(Order=1)] did not affect the results. The same properties returned as null.

If anybody has any suggestions, they'd be greatly appreciated. I'm fairly new to .NET and have been banging my head against this problem for a few days now. If any further information / code snippets are needed, please let me know. Thanks in advance.

Answer 1

How did you generate your client? You might just need to regenerate or update your client. For example, if you generated the client, then added one of those properties to the server, but did not regenerate the client, then the value would get passed back tot he client, but the client would ignore it because it doesn't know what it is.

That is my best guess, anyway...

---

Actually, reading your question again, you stated that:

The values seem to be reaching the client program though, because the response from running a SoapUI test shows the correct values in the XML.

However comparing the list of items you say are null and the soap response:

• ProductLineItems

Is null in the soap response:

<a:ProductLineItems i:nil="true"/>

• TotalTaxLines

Is null in the soap response:

<a:TotalTaxLines xmlns:b="http://schemas.datacontract.org/2004/07/Avalara.AvaTax.Adapter.TaxService"/>

So I have to assume that those are actually correctly returning null.

---

In addition, for the properties that contain these non-standard data types:

• ProductLineItem
• Avalara.AvaTax.Adapter.TaxService.TaxLines

Those two data types need to me marked as [DataContract] also, or I think ISerializable will work too.