Hi all,

I created a web service and it just has one method:

[WebService(Namespace = "")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class AssignmentService : System.Web.Services.WebService
{
    [WebMethod]
    public SoapEnvelope CreateAssignment(SoapEnvelope soapEnvelopeAssignment)
    {
    }

However, when the web reference is added to a client project, I get the following definition for the method.

        public System.Xml.XmlNode CreateAssignment(System.Xml.XmlNode soapEnvelopeAssignment) {
}

When I call the service using the web service reference, I get a SoapException:

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Message: System.Web.Services.Protocols.SoapException: Server was unable to read request. ---> System.InvalidOperationException: There is an error in the XML document. ---> System.InvalidCastException: Unable to cast object of type 'System.Xml.XmlElement' to type 'Microsoft.Web.Services3.SoapEnvelope'.
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReader1.Read1_CreateAssignment()
at Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer.Deserialize(XmlSerializationReader reader)
at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
--- End of inner exception stack trace ---
at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle)
at System.Web.Services.Protocols.SoapServerProtocol.ReadParameters()
--- End of inner exception stack trace ---
at System.Web.Services.Protocols.SoapServerProtocol.ReadParameters()
at System.Web.Services.Protocols.WebServiceHandler.CoreProcessRequest()



Stack: at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)

at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)

at AssignmentServiceTester.AssignmentService.AssignmentService.CreateAssignment(XmlNode soapEnvelopeAssignment) in C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\Projects\AssignmentService (2)\AssignmentServiceTester\Web References\AssignmentService\Reference.cs:line 176

at AssignmentServiceTester.Form1.toolStripButtonAssignment_Click(Object sender, EventArgs e) in C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\Projects\AssignmentService (2)\AssignmentServiceTester\Form1.cs:line 73



Source: System.Web.Services




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OK
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What am I doing wrong? How do I make sure that same type of parameters and return value of the web method stay in sync in both the service and the client?