web service request call SOAP request missing empty parameters

I'm new to both web services and C# so please forgive me if my question is too simple. I've searched around but cannot find an answer -- at least one based on my keywords.

I am trying to call a web service via C# (Visual Web Developer 2010 Express) but I get an error back as a response. When I call the same web service via soapUI I do not get an error. When I compare the SOAP request from C# against the SOAP request from soapUI the C# SOAP request is missing an intentionally empty parameter <aclObjectId>. When I take the empty parameter out of the soapUI request I get the same error. To me, the answer is to get C# to send the parameter even though it is empty. I tried this by setting it to null or "" but to no avail. Is there a way to force my C# web service client to send an empty parameter or perhaps send all parameters even if they do not have a value?

WSDL

<?xml version="1.0" encoding="UTF-8"?><!-- Published by JAX-WS RI at http://jax-ws.dev.java.net. RI's version is JAX-WS RI 2.1.3-b02-. --><!-- Generated by JAX-WS RI at http://jax-ws.dev.java.net. RI's version is JAX-WS RI 2.1.3-b02-. --><definitions xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="http://search.services.redacted/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://search.services.redacted/" name="EDRSearchServiceSOAPImplService">
<types>
<xsd:schema>
<xsd:import namespace="http://search.services.redacted/" schemaLocation="http://wwwdev.redacted:80/EDRSearch?xsd=1"></xsd:import>
</xsd:schema>
</types>
<message name="processSearch">
<part name="parameters" element="tns:processSearch"></part>
</message>
<message name="processSearchResponse">
<part name="parameters" element="tns:processSearchResponse"></part>
</message>
<message name="getAttributes">
<part name="parameters" element="tns:getAttributes"></part>
</message>
<message name="getAttributesResponse">
<part name="parameters" element="tns:getAttributesResponse"></part>
</message>
<message name="getACLUsers">
<part name="parameters" element="tns:getACLUsers"></part>
</message>
<message name="getACLUsersResponse">
<part name="parameters" element="tns:getACLUsersResponse"></part>
</message>
<portType name="EDRSearchServiceSOAPImpl">
<operation name="processSearch">
<input message="tns:processSearch"></input>
<output message="tns:processSearchResponse"></output>
</operation>
<operation name="getAttributes">
<input message="tns:getAttributes"></input>
<output message="tns:getAttributesResponse"></output>
</operation>
<operation name="getACLUsers">
<input message="tns:getACLUsers"></input>
<output message="tns:getACLUsersResponse"></output>
</operation>
</portType>
<binding name="EDRSearchServiceSOAPImplPortBinding" type="tns:EDRSearchServiceSOAPImpl">
<soap:binding transport="http://schemas.xmlsoap.org/soap/http" style="document"></soap:binding>
<operation name="processSearch">
<soap:operation soapAction=""></soap:operation>
<input>
<soap:body use="literal"></soap:body>
</input>
<output>
<soap:body use="literal"></soap:body>
</output>
</operation>
<operation name="getAttributes">
<soap:operation soapAction=""></soap:operation>
<input>
<soap:body use="literal"></soap:body>
</input>
<output>
<soap:body use="literal"></soap:body>
</output>
</operation>
<operation name="getACLUsers">
<soap:operation soapAction=""></soap:operation>
<input>
<soap:body use="literal"></soap:body>
</input>
<output>
<soap:body use="literal"></soap:body>
</output>
</operation>
</binding>
<service name="EDRSearchServiceSOAPImplService">
<port name="EDRSearchServiceSOAPImplPort" binding="tns:EDRSearchServiceSOAPImplPortBinding">
<soap:address location="http://wwwdev.redacted:80/EDRSearch"></soap:address>
</port>
</service>
</definitions>

C# SOAP (doesn't work)

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
  <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <getACLUsers xmlns="http://search.services.redacted/">
      <ACLUsersRequest xmlns="">
        <docbase>edmsdev</docbase>
        <aclName>my_acl</aclName>
      </ACLUsersRequest>
      <userCredentials xmlns="">
        <userName>spoonyfork</userName>
        <password>my_password</password>
        <docbase>edmsdev</docbase>
      </userCredentials>
    </getACLUsers>
  </s:Body>
</s:Envelope>

soapUI SOAP (works)

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sear="http://search.services.redacted/">
   <soapenv:Header/>
   <soapenv:Body>
      <sear:getACLUsers>
         <!--Optional:-->
         <ACLUsersRequest>
            <docbase>edmsdev</docbase>
            <aclName>my_acl</aclName>
            <aclObjectId></aclObjectId>
         </ACLUsersRequest>
         <!--Optional:-->
         <userCredentials>
            <userName>spoonyfork</userName>
            <!--Optional:-->
            <password>my_password</password>
            <!--Optional:-->
            <wsl4cookie></wsl4cookie>
            <!--Optional:-->
            <endUserForProxyId></endUserForProxyId>
            <!--Optional:-->
            <ip></ip>
            <!--Optional:-->
            <docbase>edmsdev</docbase>
         </userCredentials>
      </sear:getACLUsers>
   </soapenv:Body>
</soapenv:Envelope>

EDRSearch XSD

<?xml version="1.0" encoding="UTF-8"?><!-- Published by JAX-WS RI at http://jax-ws.dev.java.net. RI's version is JAX-WS RI 2.1.3-b02-. --><xs:schema xmlns:tns="http://search.services.redacted/" xmlns:xs="http://www.w3.org/2001/XMLSchema" version="1.0" targetNamespace="http://search.services.redacted/">

<xs:element name="getACLUsers" type="tns:getACLUsers"></xs:element>

<xs:element name="getACLUsersResponse" type="tns:getACLUsersResponse"></xs:element>

<xs:element name="getAttributes" type="tns:getAttributes"></xs:element>

<xs:element name="getAttributesResponse" type="tns:getAttributesResponse"></xs:element>

<xs:element name="processSearch" type="tns:processSearch"></xs:element>

<xs:element name="processSearchResponse" type="tns:processSearchResponse"></xs:element>

<xs:complexType name="getACLUsers">
<xs:sequence>
<xs:element name="ACLUsersRequest" type="tns:ACLUsersRequest" minOccurs="0"></xs:element>
<xs:element name="userCredentials" type="tns:UserCredentials" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="ACLUsersRequest">
<xs:sequence>
<xs:element name="docbase" type="xs:string"></xs:element>
<xs:element name="aclName" type="xs:string"></xs:element>
<xs:element name="aclObjectId" type="xs:string"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="UserCredentials">
<xs:sequence>
<xs:element name="userName" type="xs:string"></xs:element>
<xs:element name="password" type="xs:string" minOccurs="0"></xs:element>
<xs:element name="wsl4cookie" type="xs:string" minOccurs="0"></xs:element>
<xs:element name="endUserForProxyId" type="xs:string" minOccurs="0"></xs:element>
<xs:element name="ip" type="xs:string" minOccurs="0"></xs:element>
<xs:element name="docbase" type="xs:string" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="getACLUsersResponse">
<xs:sequence>
<xs:element name="return" type="tns:ACLUsersResponse" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="ACLUsersResponse">
<xs:sequence>
<xs:element name="user" type="xs:string" maxOccurs="unbounded"></xs:element>
<xs:element name="largeGroups" type="xs:string" maxOccurs="unbounded"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="processSearch">
<xs:sequence>
<xs:element name="searchRequest" type="tns:searchRequest" minOccurs="0"></xs:element>
<xs:element name="userCredentials" type="tns:UserCredentials" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="searchRequest">
<xs:sequence>
<xs:element name="version" type="xs:string"></xs:element>
<xs:element name="docbase" type="xs:string"></xs:element>
<xs:element name="searchCriteria" type="tns:logicalOp" maxOccurs="unbounded"></xs:element>
<xs:element name="maxNumberOfDocuments" type="xs:string"></xs:element>
<xs:element name="folderPaths" type="xs:string" maxOccurs="unbounded"></xs:element>
<xs:element name="metaDataList" type="xs:string" maxOccurs="unbounded"></xs:element>
<xs:element name="objectType" type="xs:string"></xs:element>
<xs:element name="documentLaunchSettings" type="tns:documentLaunchSettings"></xs:element>
<xs:element name="documentACLSettings" type="tns:documentACLSettings"></xs:element>
<xs:element name="oracleHint" type="xs:string" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="logicalOp">
<xs:sequence>
<xs:element name="type" type="xs:string"></xs:element>
<xs:element name="name" type="xs:string"></xs:element>
<xs:element name="value" type="xs:string"></xs:element>
<xs:element name="logical" type="xs:string"></xs:element>
<xs:element name="relational" type="xs:string"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="documentLaunchSettings">
<xs:sequence>
<xs:element name="launcher" type="xs:string"></xs:element>
<xs:element name="useChronicleId" type="xs:boolean"></xs:element>
<xs:element name="showLink" type="xs:boolean"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="documentACLSettings">
<xs:sequence>
<xs:element name="returnACL" type="xs:boolean"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="processSearchResponse">
<xs:sequence>
<xs:element name="return" type="tns:searchResponse" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="searchResponse">
<xs:sequence>
<xs:element name="docbase" type="xs:string" minOccurs="0"></xs:element>
<xs:element name="documents" type="tns:document" nillable="true" minOccurs="0" maxOccurs="unbounded"></xs:element>
<xs:element name="numberOfDocuments" type="xs:string" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:comple开发者_StackOverflow中文版xType name="document">
<xs:sequence>
<xs:element name="objectId" type="xs:string"></xs:element>
<xs:element name="linkLocation" type="xs:string"></xs:element>
<xs:element name="metaDataList" type="tns:metaDataItem" maxOccurs="unbounded"></xs:element>
<xs:element name="aclInfo" type="tns:ACLInfo" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="metaDataItem">
<xs:sequence>
<xs:element name="name" type="xs:string"></xs:element>
<xs:element name="value" type="xs:string"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="ACLInfo">
<xs:sequence>
<xs:element name="ACLName" type="xs:string"></xs:element>
<xs:element name="ACLObjectId" type="xs:string"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="getAttributes">
<xs:sequence>
<xs:element name="attributesRequest" type="tns:objectType" minOccurs="0"></xs:element>
<xs:element name="userCredentials" type="tns:UserCredentials" minOccurs="0"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="objectType">
<xs:sequence>
<xs:element name="docbase" type="xs:string"></xs:element>
<xs:element name="objectType" type="xs:string"></xs:element>
</xs:sequence>
</xs:complexType>

<xs:complexType name="getAttributesResponse">
<xs:sequence>
<xs:element name="return" type="xs:string" minOccurs="0" maxOccurs="unbounded"></xs:element>
</xs:sequence>
</xs:complexType>
</xs:schema>

C# code

ServiceReference1.UserCredentials uc = new ServiceReference1.UserCredentials();
uc.userName = "spoonyfork";
uc.password = "my_password";
uc.docbase = "edmsdev";

ServiceReference1.ACLUsersRequest aurt = new ServiceReference1.ACLUsersRequest();
aurt.aclName = "my_acl";
aurt.docbase = "edmsdev";

ServiceReference1.EDRSearchServiceSOAPImplClient client = new ServiceReference1.EDRSearchServiceSOAPImplClient();
ServiceReference1.ACLUsersResponse aure = new ServiceReference1.ACLUsersResponse();
aure = client.getACLUsers(aurt, uc);

First, you can try to declare aclObjectId property to serialize even if it is null. For that you'll need to find the definition of class ACLUsersRequest and add

[System.Xml.Serialization.XmlElementAttribute(IsNullable=true)]

for that property. That 'll include it into SOAP request as <aclObjectId xsi:nil="true" />

Second, you can simply declare that property as string.Empty:

EDRSearchServiceSOAPImplClient client = new EDRSearchServiceSOAPImplClient();
var test = client.getACLUsers(
    new ACLUsersRequest() {
        aclName = "my_acl",
        docbase = "qwe",
        aclObjectId=string.Empty },//this should do the trick
    new UserCredentials() {
        userName = "lala",
        password = "123",
        docbase = "qwe" });

That 'll include it into SOAP request as <aclObjectId /> which is equal to <aclObjectId></aclObjectId>

If neither of methods will work, then you are dealing with really bad web service provider and need to implement self written client that will format message as forced by provider.

Only thing I have managed to find so far:

http://www.w3.org/TR/2007/REC-soap12-part2-20070427/

4.2.1
Applications MAY process invocations with missing parameters but also MAY fail to process the invocation and return a fault.

Did you generate a web reference manually? Can you supply the appropriate WSDL? + I can update this answer

<operation name="getACLUsers">
    <soap:operation soapAction=""></soap:operation>
    <input>
        <soap:body use="literal"></soap:body>
    </input>
    <output>
        <soap:body use="literal"></soap:body>
    </output>
</operation>

To me this doesn't look like there are multiple parameters at the SOAP level, just the one say XML or string parameter. Does getAclUsers have multiple parameters?

I have limited SOAP knowledge I will admit, but there's nothing in the WSDL listing any parameters... Perhaps you're serialising to XML and the XML serialisation options are what you should be looking at instead?