調用回調方法時無法訪問處置對象

Question

我有一個雙工TCP IP WCF服務。我目前正在對它進行單元測試。

在我的測試中，我設置了一個新的服務器，創建一個新的ChannelFactory，創建InstanceContext並進行調用。

然後，我觸發事件（它在服務器端的模擬），並且服務器給我這個例外，當它試圖達到的客戶：在mscorlib程序「System.ObjectDisposedException」：

拋出異常.dll 附加信息：無法訪問處置的對象。

重要的一點，只有當我在一行中運行所有測試（按順序執行但在相同的執行中）時，纔會發生這種情況。

沒有什麼特別之處我的服務：

[ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(IMyServiceCallback))] 
public interface IMyService{ 
    [OperationContract] 
    void SomeVariousMethods(); 
} 

[ServiceContract] 
public interface IMyServiceCallback 
{ 
    [OperationContract] 
    void HandleMessageFromServer(String message); 
} 


[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)] 
public class MyService : IMyService{ 
    public MyService(ISomeServerComponent component){ 
     component.OnMessage += OnMessageReceived; 
    } 

    public void SomeVariousMethods(){ 
     //... 
    } 

    private void OnMessageReceived(object sender, EventArgs<String> e){ 
     IMyServiceCallback callback = OperationContext.Current.GetCallbackChannel<IMyServiceCallback>(); 
     callBack.HandleMessageFromServer(e.Data);//Crash here 
    } 
} 

這裏是我當前如何單元測試它（不完全是，我有很多的這個已經在一些助手被提取：

[TestFixture] 
public class MyServiceTest:IMyServiceCallback{ 

    private Mock<ISomeServerComponent> _mock; 

    [OneTimeSetUp] 
    public void Setup(){ 
     //... Creating a mock for the ISomeServerComponent that the MyService receives 
    } 

    [Test] 
    public void TestSomeVariousMethods(){ 
     string serviceName = nameof(TestSomeVariousMethods); 
     using(ServiceHost host = CreateServer(_mock.Object,serviceName)){ 
      using (IMyService service = CreateClient(serviceName, this)){ 
       service.SomeVariousMethods(); 
      } 
     } 
    } 

    [Test] 
    public void TestCallback(){ 
     string serviceName = nameof(TestSomeVariousMethods); 
     using(ServiceHost host = CreateServer(_mock.Object,serviceName)){ 
      using (IMyService service = CreateClient(serviceName, this)){ 
       _mock.TriggerCallBack(); 
       //Assert-that-the-flag-has-been-set 
      } 
     } 
    } 

    public void HandleMessageFromServer(String msg){ 
     //Flag that this method has been called 
    } 




    private ServiceHost CreateServer(ISomeServerComponent mock, string serviceName){ 
     UnityServiceHost serviceHost = new UnityServiceHost(m_container);//This extends ServiceHost to be able to inject some objects to my services 
     NetTcpBinding binding = new NetTcpBinding(SecurityMode.None); 
     binding.ReliableSession.Enabled = true; 
     binding.Security.Transport.ClientCredentialType = TcpClientCredentialType.None; 
     binding.MaxBufferPoolSize = Int64.MaxValue; 
     binding.MaxBufferSize = Int32.MaxValue; 
     binding.MaxReceivedMessageSize = Int32.MaxValue; 

     Uri uri = new Uri(String.Format("net.tcp://{0}:{1}/{2}", IPAddress.Any, 9999, serviceName)); 

     ServiceEndpoint serviceEndpoint = new ServiceEndpoint(ContractDescription.GetContract(typeof(IMyService)), binding, uri); 
     serviceEndpoint.EndpointBehaviors.Add(new ProtoEndpointBehavior()); 

     serviceHost.AddServiceEndpoint(serviceEndpoint); 
     return serviceHost; 
    } 

    private IMyService CreateClient(string serviceName, IMyServiceCallback callback){ 
     UnityServiceHost serviceHost = new UnityServiceHost(m_container);//This extends ServiceHost to be able to inject some objects to my services 
     NetTcpBinding binding = new NetTcpBinding(SecurityMode.None); 
     binding.ReliableSession.Enabled = true; 
     binding.Security.Transport.ClientCredentialType = TcpClientCredentialType.None; 
     binding.MaxBufferPoolSize = Int64.MaxValue; 
     binding.MaxBufferSize = Int32.MaxValue; 
     binding.MaxReceivedMessageSize = Int32.MaxValue; 

     Uri uri = new Uri(String.Format("net.tcp://{0}:{1}/{2}", IPAddress.Loopback, 9999, serviceName)); 


     InstanceContext context = new InstanceContext(callBack); 
     DuplexChannelFactory channelFactory = new DuplexChannelFactory<T>(context, binding, new EndpointAddress(uri)); 
     return channelFactory.CreateChannel() 
    } 
} 

有趣的是，所有這一切的時候，我只運行TestCallback測試工作，但如果我運行的類的所有測試，它失敗了，就像如果第二次，InstanceContext沒有正確創建回調。

任何想法如何避免這種情況？

Answer 1

我終於找到了問題。我覺得有點愚蠢，但事實上，在服務實現中，我沒有正確註銷OnMessage，所以當事件被觸發時，以前的服務實例試圖與已經關閉的客戶端進行通信。