如何通过WCF SOAP服务访问EF导航属性？

Posted 2023-01-16

我正在为此WCF错误挣扎一段时间，没有任何运气。基本上，我想绑定[[通过WCF服务获取具有导航属性和已连接对象的实体Poco。我的EF v6代码成功地从数据库中获取了所有相关实体的Poco

Poco debug view

但是当我尝试

通过WCF服务访问此实体

时，我看到以下错误-[收到对http://localhost:8734/Design_Time_Addresses/BusinessLogicServicesLayer/userServices/的HTTP响应时发生错误。这可能是由于服务端点绑定未使用HTTP协议。这也可能是由于服务器终止了HTTP请求上下文（可能是由于服务关闭了）。有关更多详细信息，请参见服务器日志。服务器堆栈跟踪：在System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException（WebException webException，HttpWebRequest请求，HttpAbortReason abortReason）在System.ServiceModel.Channels.HttpChannelFactory1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) at System.ServiceModel.Channels.RequestChannel.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 IuserServicesQuery.getCompleteUserSnapshot(String emailAddress) at IuserServicesQueryClient.getCompleteUserSnapshot(String emailAddress) Inner Exception: The underlying connection was closed: An unexpected error occurred on a receive. at System.Net.HttpWebRequest.GetResponse() at System.ServiceModel.Channels.HttpChannelFactory1.HttpRequestChannel.HttpChannelRequest.WaitForReply（TimeSpan超时）处内部异常：无法从传输连接中读取数据：远程主机强行关闭了现有连接。在System.Net.Sockets.NetworkStream.Read（Byte []缓冲区，Int32偏移量，Int32大小）在System.Net.PooledStream.Read（Byte []缓冲区，Int32偏移量，Int32大小）在System.Net.Connection.SyncRead（HttpWebRequest请求，布尔userRetrievedStream，布尔probeRead）内部异常：远程主机强行关闭了现有连接在System.Net.Sockets.Socket.Receive（Byte []缓冲区，Int32偏移量，Int32大小，SocketFlags socketFlags）在System.Net.Sockets.NetworkStream.Read（字节[]缓冲区，Int32偏移量，Int32大小）

我的AppConfig文件看起来像这样-

<endpoint address="" behaviorConfiguration="MyBehavior" binding="basicHttpBinding" bindingConfiguration="IncreasedTimeout" name="BasicHttpEndpoint" contract="BusinessLogicServicesLayer.IuserServicesQuery" listenUriMode="Explicit"> <identity> <dns value="localhost" /> </identity> </endpoint>

&&

<bindings> <basicHttpBinding> <binding name="IncreasedTimeout" openTimeout="12:00:00" receiveTimeout="12:00:00" closeTimeout="12:00:00" sendTimeout="12:00:00"> </binding> </basicHttpBinding> </bindings>

。。
<behaviors>
  <endpointBehaviors>
    <behavior name="MyBehavior">
      <dataContractSerializer maxItemsInObjectGraph="2147483646" />
    </behavior>
  </endpointBehaviors>
  <serviceBehaviors>

有人可以帮忙或为我指出正确的方向

答案

这是因为返回数据时，序列化失败，导致WCF服务自动停止。

解决方案：

我们可以在返回数据之前将代理类序列化为所需的实体。

这里是一个演示，学生类包含其他实体的导航属性：

public Student Getstu() CodeFirstDBContext codeFirstDBContext = new CodeFirstDBContext(); Student student =codeFirstDBContext.Student.Find(1); var serializer = new DataContractSerializer(typeof(Student), new DataContractSerializerSettings() DataContractResolver = new ProxyDataContractResolver() ); using (var stream = new MemoryStream()) serializer.WriteObject(stream, student); stream.Seek(0, SeekOrigin.Begin); var stu = (Student)serializer.ReadObject(stream); return stu;

这是客户端将调用的方法。
     ServiceReference1.ServiceClient serviceClient = new ServiceReference1.ServiceClient();
        var stu = serviceClient.Getstu();

客户端将成功呼叫。
UPDATE禁用加载加载也可以解决此问题：
      public class CodeFirstDBContext : DbContext

    public CodeFirstDBContext() : base("name=DBConn")
    
        this.Configuration.ProxyCreationEnabled = false;
        this.Configuration.LazyLoadingEnabled = false;
        Database.SetInitializer(new CreateDatabaseIfNotExists<CodeFirstDBContext>());