WCF Contract first: complexType has already been declared

Question

I am using svcutil.exe to generate a service endpoint based on a contract from an external source.

It seems to work as intended, but the service is not able to expose an endpoint to others.

Specifically, when I try to GET the WSDL for the service, an exception is thrown with the following error:

System.InvalidOperationException: An exception was thrown in a call to a WSDL export extension: System.ServiceModel.Description.XmlSerializerOperationBehavior contract: http://tempuri.org/xml/wsdl/soap11/DistributionService/1/port:DistributionReceiverWebServicePort ----> System.Xml.Schema.XmlSchemaException: The complexType 'http://tempuri.org/xml/wsdl/soap11/DistributionService/1/types:FejlType' has already been declared.

But - the type FejlType type is only declared once and is a very simple class:

[System.SerializableAttribute()]
[System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://tempuri.org/xml/wsdl/soap11/DistributionService/1/types")]
[System.Runtime.Serialization.DataContractAttribute(Name = "FejlType", Namespace = "http://tempuri.org/xml/wsdl/soap11/DistributionService/1/types")]
public class FejlType : object, System.Runtime.Serialization.IExtensibleDataObject
{
    private System.Runtime.Serialization.ExtensionDataObject extensionDataField;
    private string FejlKodeField;
    private string FejlTekstField;

    public System.Runtime.Serialization.ExtensionDataObject ExtensionData
    {
        get {return this.extensionDataField;}
        set {this.extensionDataField = value;}
    }

    [System.Runtime.Serialization.DataMemberAttribute(IsRequired = true, EmitDefaultValue = false)]
    public string FejlKode
    {
        get {return this.FejlKodeField;}
        set {this.FejlKodeField = value;}
    }

    [System.Runtime.Serialization.DataMemberAttribute(IsRequired = true, EmitDefaultValue = false)]
    public string FejlTekst
    {
        get {return this.FejlTekstField;}
        set {this.FejlTekstField = value;}
    }
}

I am totally in the dark here - why does WCF complain about this when exporting the WSDL?

Jesper Lund Stocholm Jesper Lund Stocholm · Accepted Answer · 2015-02-26T08:20:50

I found the cause of the problem.

FYI: the WSDL originates from KOMBIT (a Danish Government IT-thingy) and the WSDL is a part of their data hub (Serviceplatformen)

I discovered that the service classes generated by svcutil.exe had the type FejlType implemented twice - both as partial classes, btw. One of them had a specific .net namespace prefix and the other did not have its own prefix. What was causing the problem was an XmlTypeAttribute on the types - each of them exposing the same xml namespace. So even though the service classes did compile, they exposed the same xml type specification - causing the exception I reported here.

WCF Contract first: complexType has already been declared

1 Answers