接收对我的服务的 HTTP 响应时出现 WCF 错误

Question

大家好，我使用 WCF 创建了一个服务，但是当我测试我的服务时，有些服务已成功完成，为什么有些服务会出现以下错误。关于如何解决这些问题的任何想法？谢谢

An error occurred while receiving the HTTP response to http://localhost:8733/PortOperation/Operator_Service/ws. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.

Server stack trace: 
at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.ClientReliableChannelBinder`1.RequestClientReliableChannelBinder`1.OnRequest(TRequestChannel channel, Message message, TimeSpan timeout, MaskingMode maskingMode)
at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout, MaskingMode maskingMode)
at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Security.SecuritySessionClientSettings`1.SecurityRequestSessionChannel.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]: 
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at IOperator_Service.GetAllUser(String ConnectionString)
at Operator_ServiceClient.GetAllUser(String ConnectionString)

Inner Exception:
The underlying connection was closed: An unexpected error occurred on a receive.
at System.Net.HttpWebRequest.GetResponse()
at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)

Inner Exception:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)

Inner Exception:
An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

Answer 1

发生此类错误的情况很多。

第一

检查您是否提供了正确的 [DataContract] 和 [DataMember]？如果未提供，则会发生此类错误。您必须在响应中传递的类上方写入 [DataContract]，并在进入客户端响应的类成员上方写入 [DataMember]。

例如。

[DataContract]
class Program
{
  [DataMember] 
  public string Example{get;set}
}

第二

如果传递了一些数据类型的最小值，请检查响应。这意味着某个时间数据成员在其取最小值时未初始化。 例如int 的 minValue 是 '-2147483648' 所以有时它不能被序列化并抛出错误。

如果您想跟踪此类错误，请在您的服务器端 web.config 中添加以下代码

<system.diagnostics>
 <sources>
  <source name="System.ServiceModel" switchValue="Information, ActivityTracing"    propagateActivity="true">
   <listeners>
     <add name="traceListener" type="System.Diagnostics.XmlWriterTraceListener"      initializeData= "D:\Traces.svclog"/>
   </listeners>
  </source>
 </sources>
</system.diagnostics>

我想它会对你有所帮助。

Answer 2

我能够解决问题。

如果您使用的是 EF“代码优先”方法并且您希望使用 WCF 访问您的数据，您应该考虑不要在 poco 类中使用“virtual”关键字启用延迟加载，因为 WCF序列化无法序列化动态代理数据。