WCF服务引发“未预期类型[…]。 即使已经使用XmlInclude，也要使用XmlInclude […]”

Question

I have a WCF service (started from code) that uses an object not defined in the service definition. Because of that I have to use the [XmlInclude] attribute to make WCF understand how to serialize it. For some reason this doesn't work and WCF still complains (I found the exception using tracing) that I have to use [XmlInclude] for the type already defined.

What am I missing here?

Code to start WCF service

ServiceHost host = new ServiceHost(typeof(MyService), "http://localhost/myservice");

ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
smb.HttpGetEnabled = true;
smb.MetadataExporter.PolicyVersion = PolicyVersion.Policy12;

host.Description.Behaviors.Add(smb);
host.Open();

Service implementation

[WebService(Namespace = "http://services.mysite.com/MyService")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
public class MyService : WebService, IMyService {

    [WebMethod]
    [XmlInclude(typeof(InnerObject))]
    public MyReturnObject Test() {
        return new MyReturnObject(new InnerObject());
    }
}

Service definition / interface

[ServiceContract]
public interface IMyService {

    [OperationContract, XmlSerializerFormat(Style = OperationFormatStyle.Document)]
    MyReturnObject Test();
}

Return types

The MyReturnObject class contains a generic object that can contain whatever I want. For this example I include a InnerObject type as defined above, and the type definitions look like so.

[KnownType(typeof(InnerObject))]
public class MyReturnObject {
    public object Content { get; set; }

    public MyReturnObject(object content) {
        Content = content;
    }
}

public class InnerObject {
    public int Foo;
    public string Bar;
    // And some other properties
}

Complete exception

System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089

The type InnerObject was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

Answer 1

您应该在wcf服务上使用[ServiceKnownType]