serializing custom objects

Question

I have 2 classes that derive from a generic base class.

[Serializable()]
[XmlInclude(typeof(User))]
[XmlInclude(typeof(File))]
public class BaseEntity<T>
{
    private long id;

    [XmlAttribute(AttributeName = "id")]
    public virtual long ID
    {
        get { return this.id; }
        set { this.id = value; }
    }
}

[Serializable()]
public class User : BaseEntity<User>
{
    private string userName;
    private string sharedDirectory;
    private bool connected;

    [XmlAttribute(AttributeName = "UserName")]
    public virtual string UserName 
    {
        get { return this.userName; }
        set { this.userName = value; } 
    }

    [XmlAttribute(AttributeName = "SharedDirectory")]
    public virtual string SharedDirectory
    {
        get { return this.sharedDirectory; }
        set { this.sharedDirectory = value; }
    }

    [XmlAttribute(AttributeName = "IsConnected")]
    public virtual bool IsConnected
    {
        get { return this.connected; }
        set { this.connected = value; }
    }
}

[Serializable()]
public class File : BaseEntity<File>
{
    private string name;
    private User user;

    [XmlAttribute(AttributeName = "Name")]
    public virtual string Name
    {
        get { return this.name; }
        set { this.name = value; }
    }

    [XmlElement(ElementName = "User", Type = typeof(User))]
    public virtual User User
    {
        get { return this.user; }
        set { this.user = value; }
    }
}

I have a web service (not WCF service) that return a List of Files (List). When i call the service, the method is preformed but the serializing process fails. This is the Exception I get:

System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException: The type Castle.Proxies.UserProxy was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.\n at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write4_User(String n, String ns, User o, Boolean isNullable, Boolean needType)\n at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write6_File(String n, String ns, File o, Boolean isNullable, Boolean needType)\n at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write7_GetFilesByNameResponse(Object[] p)\n at Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer1.Serialize(Object objectToSerialize, XmlSerializationWriter writer)\n at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)\n --- End of inner exception stack trace ---\n at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)\n at System.Web.Services.Protocols.SoapServerProtocol.WriteReturns(Object[] returnValues, Stream outputStream)\n at System.Web.Services.Protocols.WebServiceHandler.WriteReturns(Object[] returnValues)\n at System.Web.Services.Protocols.WebServiceHandler.Invoke()\n --- End of inner exception stack trace ---

Any one knows why?

Answer 1

Its because that i used lazy=true and when i serialized my objects, the serializer tried to serialize the Proxy object which is NOT allowed. when i changed the mapping to lazy=false it worked!