WCF Read data issue from service - wcf

Question

I am tying to get the generic List of user List<User> object from my web service to my web application. probably this is common issue. i searched a lot but got different remedies with each link. so finally i decide to ask to chaps over here... anyways
I am using console application for fetching the data from my hosted wcf web service. where as my WCf web service having the Entity framework 4.1. am using objects from its model class. when i tried to add service reference to my web application , it typically generates the proxy in web app. i am able to post data means i could create user. but while getusers which is returning List , getting following exceptions...:
Exception:
An error occurred while receiving the HTTP response to
http://myserver/AdminService/MyAdminService.svc. 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.
Inner Exception is :
The underlying connection was closed: An unexpected error occurred
on a receive
and inner-inner exception is : Unable to read data from the
transport connection: An existing connection was forcibly closed by
the remote host.
with message : An existing connection was forcibly closed by the
remote host
Error Code :10054
Where as Event log saying :
A message was not logged.
Exception: System.ServiceModel.CommunicationException: There was
an error while trying to serialize parameter
http://tempuri.org/:getUsersResult. The InnerException message was
'Type
'System.Data.Entity.DynamicProxies.User_00DEC686D7E21DB0D84B595F647A03FFB4943938F76E8C3DBBE0F77F8BC29A1D'
with data contract name
'User_00DEC686D7E21DB0D84B595F647A03FFB4943938F76E8C3DBBE0F77F8BC29A1D:http://schemas.datacontract.org/2004/07/System.Data.Entity.DynamicProxies'
is not expected. Consider using a DataContractResolver or add any
types not known statically to the list of known types - for example,
by using the KnownTypeAttribute attribute or by adding them to the
list of known types passed to DataContractSerializer.'. Please see
InnerException for more details. --->
System.Runtime.Serialization.SerializationException: Type
'System.Data.Entity.DynamicProxies.User_00DEC686D7E21DB0D84B595F647A03FFB4943938F76E8C3DBBE0F77F8BC29A1D'
with data contract name
'User_00DEC686D7E21DB0D84B595F647A03FFB4943938F76E8C3DBBE0F77F8BC29A1D:http://schemas.datacontract.org/2004/07/System.Data.Entity.DynamicProxies'
is not expected. Consider using a DataContractResolver or add any
types not known statically to the list of known types - for example,
by using the KnownTypeAttribute attribute or by adding them to the
list of known types passed to DataContractSerializer.
at
System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract
dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean
verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type
declaredType)
at
System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithXsiType(XmlWriterDelegator
xmlWriter, Object obj, RuntimeTypeHandle objectTypeHandle, Type
objectType, Int32 declaredTypeID, RuntimeTypeHandle
declaredTypeHandle, Type declaredType)
at
System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator
xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType,
Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
at
System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerializeReference(XmlWriterDelegator
xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType,
Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
at WriteArrayOfUserToXml(XmlWriterDelegator , Object ,
XmlObjectSerializerWriteContext , CollectionDataContract )
at
System.Runtime.Serialization.CollectionDataContract.WriteXmlValue(XmlWriterDelegator
xmlWriter, Object obj, XmlObjectSerializerWriteContext context)
at
System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator
writer, Object graph, DataContractResolver dataContractResolver)
at
System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator
writer, Object graph, DataContractResolver dataContractResolver)
at
System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator
writer, Object graph, DataContractResolver dataContractResolver)
at
System.Runtime.Serialization.XmlObjectSerializer.WriteObject(XmlDictionaryWriter
writer, Object graph)
at
System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameterPart(XmlDictionaryWriter
writer, PartInfo part, Object graph)
--- End of inner exception stack trace ---
at
System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameterPart(XmlDictionaryWriter
writer, PartInfo part, Object graph)
at
System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameter(XmlDictionaryWriter
writer, PartInfo part, Object graph)
at
System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeBody(XmlDictionaryWriter
writer, MessageVersion version, String action, MessageDescription
messageDescription, Object returnValue, Object[] parameters, Boolean
isRequest)
at
System.ServiceModel.Dispatcher.OperationFormatter.OperationFormatterMessage.OperationFormatterBodyWriter.OnWriteBodyContents(XmlDictionaryWriter
writer)
at
System.ServiceModel.Channels.BodyWriter.WriteBodyContents(XmlDictionaryWriter
writer)
at
System.ServiceModel.Channels.Message.ToString(XmlDictionaryWriter
writer)
at
System.ServiceModel.Diagnostics.MessageLogTraceRecord.WriteTo(XmlWriter
writer)
at
System.ServiceModel.Diagnostics.MessageLogger.LogInternal(MessageLogTraceRecord
record)
at
System.ServiceModel.Diagnostics.MessageLogger.LogMessageImpl(Message&
message, XmlReader reader, MessageLoggingSource source)
at
System.ServiceModel.Diagnostics.MessageLogger.LogMessage(Message&
message, XmlReader reader, MessageLoggingSource source)
Process Name: w3wp
Process ID: 5928
What should be this issue. me and team searching for this since 3 days. but unfortunately not overcome so far...
I tried lot of stuffs like add serializable attribute, endpoint modifications ... i can not recollect all :) ... probably you may give us right directions...

Answer 1

The reason is that EF classes are by default proxied at runtime to support lazy loading and dynamic change tracking. So you don't serialize User class but class derived from User at runtime. WCF doesn't like that. Turn off proxy creation on your context.
context.Configuration.ProxyCreationEnabled = false;