CommunicationException提出时返回一个EF4POCO从WCF服务操作

Question

以下提出了一个代码 系统。ServiceModel.CommunicationException.它的呼WCF服务的操作所谓 登录 它返回EF4POCO:

        var client = new AuthServiceReference.AuthServiceClient();

        try
        {
            Console.Write("Trying to logon...");
            var session = client.Login("user", "password"); // throws CommunicationException
            Console.WriteLine("done!");
            Console.WriteLine("Session ID: {0}. Expires {1}", 
                session.Id, session.UtcExpires.ToLocalTime());
        }
        finally
        {
            client.Close();
        }

我一直在调试和寻找几个小时试图找出 为什么 发生这种情况及如何解决它。我发现了什么迄今为止:

1. 这可能是一系列化问题
2. 当我删除了 DataMemberAttribute 从 届会 类的 所有人 部件，例外的消失，但这意味着它不会串行的。

我会感激，如果任何人都可以揭示一些关于这个问题。

下面是代码，用于服务合同、POCO类：

[ServiceContract]
public interface IAuthService
{
    [OperationContract]
    Session Login(string username, string passwordHash);

    [OperationContract]
    void Logout(Guid sessionId);
}

[DataContract]
public class Session
{
    [DataMember]
    public Guid Id { get; set; }

    [DataMember]
    public DateTime UtcCreated { get; set; }

    [DataMember]
    public DateTime UtcExpires { get; set; }

    [DataMember] // serializes correctly if commented out
    public virtual User Owner { get; set; }

    public static Session Create(User owner)
    {
        return new Session
        {
            Owner = owner,
            Id = Guid.NewGuid(),
            UtcCreated = DateTime.UtcNow,
            UtcExpires = DateTime.UtcNow.AddDays(1)
        };
    }
}

[DataContract]
public class User
{
    [DataMember]
    public int Id { get; set; }

    [DataMember]
    public string Name { get; set; }

    [DataMember]
    public string PasswordHash { get; set; }

    [DataMember]
    public string PasswordSalt { get; set; }

    [DataMember]
    public bool IsContributor { get; set; }

    [DataMember]
    public bool IsConfirmed { get; set; }

    [DataMember]
    public bool IsAdmin { get; set; }

    [DataMember]
    public string Email { get; set; }

    [DataMember]
    public virtual ICollection<Post> Posts { get; set; }

    [DataMember]
    public virtual ICollection<Comment> Comments { get; set; }
}

Answer 1

事实证明这是一个已知的问题时列化POCO代理与WCF。这里有一个 MSDN walkthough 这解释了如何使用它 系统。数据。对象。ProxyDataContractResolver.

基本上，你创建一个新的类称为 ApplyDataContractResolverAttribute 并将其应用于服务的方法返回POCOS:

[ServiceContract]
public interface IAuthService
{
    [OperationContract]
    [ApplyDataContractResolver]
    Session Login(string username, string passwordHash);
}

---

using System;
using System.Data.Objects;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;

namespace WcfExampleBlog.Services
{
    public class ApplyDataContractResolverAttribute : Attribute, IOperationBehavior
    {
        #region IOperationBehavior Members

        public void AddBindingParameters(OperationDescription description, BindingParameterCollection parameters)
        {
        }

        public void ApplyClientBehavior(OperationDescription description, ClientOperation proxy)
        {
            var dataContractSerializerOperationBehavior =
                description.Behaviors.Find<DataContractSerializerOperationBehavior>();
            dataContractSerializerOperationBehavior.DataContractResolver =
                new ProxyDataContractResolver();
        }

        public void ApplyDispatchBehavior(OperationDescription description, DispatchOperation dispatch)
        {
            var dataContractSerializerOperationBehavior =
                description.Behaviors.Find<DataContractSerializerOperationBehavior>();
            dataContractSerializerOperationBehavior.DataContractResolver =
                new ProxyDataContractResolver();
        }

        public void Validate(OperationDescription description)
        {
            // Do validation.
        }

        #endregion
    }
}

Answer 2

我假定的"用户"类是一个定制的课吗？如果是这样，你需要添加这只是下面的与属性：

[KnownType(typeof(User))]

你还需要设置你的[数据成员]和[与]属性用户类别。