当我尝试使用循环引用（POCO）序列化实体框架类时，我收到此错误。它无法序列化包含RelationshipManager的代理类。
我尝试了http://json.codeplex.com/discussions/214093中列出的'ToList（）'方法，但仍然没有运气。有什么想法吗？
以下是我收到的异常示例。
System.Reflection.TargetInvocationException was unhandled by user code
Message=Exception has been thrown by the target of an invocation.
Source=mscorlib
StackTrace:
at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner)
at System.RuntimeMethodHandle.InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeType typeOwner)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)
at Newtonsoft.Json.Serialization.JsonContract.InvokeOnSerializing(Object o, StreamingContext context) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonContract.cs:line 111
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 293
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 117
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.WriteMemberInfoProperty(JsonWriter writer, Object memberValue, JsonProperty property, JsonContract contract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 204
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 328
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 117
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.WriteMemberInfoProperty(JsonWriter writer, Object memberValue, JsonProperty property, JsonContract contract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 204
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 328
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 117
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 429
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 127
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 70
at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\JsonSerializer.cs:line 451
at Newtonsoft.Json.JsonSerializer.Serialize(JsonWriter jsonWriter, Object value) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\JsonSerializer.cs:line 443
at Newtonsoft.Json.JsonConvert.SerializeObject(Object value, Formatting formatting, JsonSerializerSettings settings) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\JsonConvert.cs:line 591
at Route25.Events.API.Formatters.JsonPFormatter.OnWriteToStream(Type type, Object value, Stream stream, HttpContentHeaders contentHeaders, TransportContext context) in E:\Projects\Route25.Events\Route25.Events.API\Formatters\JsonPFormatter.cs:line 75
at Microsoft.ApplicationServer.Http.MediaTypeFormatter.WriteToStream(Type type, Object instance, Stream stream, HttpContentHeaders contentHeaders, TransportContext context)
at Microsoft.ApplicationServer.Http.ObjectContent.WriteToStreamInternal(Stream stream, TransportContext context)
at Microsoft.ApplicationServer.Http.ObjectContent.SerializeToStream(Stream stream, TransportContext context)
at System.Net.Http.HttpContent.CopyTo(Stream stream, TransportContext context)
at System.Net.Http.HttpContent.CopyTo(Stream stream)
at Microsoft.ApplicationServer.Http.Channels.HttpMessageEncoderFactory.HttpMessageEncoder.WriteMessage(Message message, Stream stream)
at Microsoft.ApplicationServer.Http.Channels.HttpMessageEncoderFactory.HttpMessageEncoder.WriteMessage(Message message, Int32 maxMessageSize, BufferManager bufferManager, Int32 messageOffset)
at System.ServiceModel.Channels.HttpOutput.SerializeBufferedMessage(Message message)
at System.ServiceModel.Channels.HttpOutput.SendAsyncResult.SendWithoutChannelBindingToken()
at System.ServiceModel.Channels.HttpOutput.SendAsyncResult.Send()
at System.ServiceModel.Channels.HttpOutput.SendAsyncResult..ctor(HttpOutput httpOutput, Boolean suppressEntityBody, TimeSpan timeout, AsyncCallback callback, Object state)
at System.ServiceModel.Channels.HttpOutput.BeginSend(TimeSpan timeout, AsyncCallback callback, Object state)
at System.ServiceModel.Channels.HttpRequestContext.ReplyAsyncResult.SendResponse()
at System.ServiceModel.Channels.HttpRequestContext.ReplyAsyncResult..ctor(HttpRequestContext context, Message message, TimeSpan timeout, AsyncCallback callback, Object state)
at System.ServiceModel.Channels.HttpRequestContext.OnBeginReply(Message message, TimeSpan timeout, AsyncCallback callback, Object state)
at System.ServiceModel.Activation.HostedHttpContext.OnBeginReply(Message message, TimeSpan timeout, AsyncCallback callback, Object state)
at System.ServiceModel.Channels.RequestContextBase.BeginReply(Message message, TimeSpan timeout, AsyncCallback callback, Object state)
at Microsoft.ApplicationServer.Http.Channels.HttpMessageEncodingRequestContext.BeginReply(Message message, TimeSpan timeout, AsyncCallback callback, Object state)
at Microsoft.ApplicationServer.Http.Channels.HttpMessageHandlerChannel.ReceiveAsyncResultBase.HttpMessageHandlerRequestContext.ReplyAsyncResult.ContinueReplyPath(HttpResponseMessage httpResponse)
InnerException: System.InvalidOperationException
Message=The RelationshipManager object could not be serialized. This type of object cannot be serialized when the RelationshipManager belongs to an entity object that does not implement IEntityWithRelationships.
Source=System.Data.Entity
StackTrace:
at System.Data.Objects.DataClasses.RelationshipManager.OnSerializing(StreamingContext context)
InnerException:
复制只需创建两个相互引用的类，并使用代码优先的dbcontext模型。
答案 0 :(得分：0)
如果问题确实存在于循环引用中，请检查this thread以获取帮助。但是您不应该序列化您的实体 - 如果序列化程序尝试序列化RelationshipManager，您应该序列化自定义对象而不是实体，因为RelationshipManager是实体的“基础架构”部分 - 它不是您真正的数据的一部分需要序列化，并且很可能这部分对于你想要传递Json对象的目标系统没有意义。