I have the class:
[Serializable]
[System.Runtime.Serialization.DataContract(IsReference = true)]
public class SymbolElem
{
public SymbolElem() // Constructor
{
Children = new List<SymbolElem>();
}
public List<SymbolElem> Children { get; set; }
public string Name { get; set; }
}
and I will like to have a service that will return me a SymbolElem using named pipes. At the beginning I thought I was having an error because I where returning a lot of objects.
Anyways here is the method on the service:
public SymbolElem TestMethod()
{
Common.SymbolElem root = new Common.SymbolElem() {
Name="root"
};
Common.SymbolElem child = new Common.SymbolElem() {
Name = "child"
};
root.Children.Add(child);
return root;
}
That works OK but when I do something like:
public SymbolElem TestMethod()
{
Common.SymbolElem root = new Common.SymbolElem() {
Name="root"
};
Common.SymbolElem child = new Common.SymbolElem() {
Name = "child"
};
root.Children.Add(child);
child.Children.add(root); // <------------ this causes an exception after returning s1!!!!
return root;
}
Here is the exception:
System.ServiceModel.Dispatcher.NetDispatcherFaultException was unhandled
Message=The formatter threw an exception while trying to deserialize the message: There was an error while trying to deserialize parameter http://tempuri.org/:GetSymbolsResult. The InnerException message was ''EndElement' 'SymbolElem' from namespace 'http://schemas.datacontract.org/2004/07/SymbolFileParser.Common' is not expected. Expecting element '_x003C_BitOffset_x003E_k__BackingField'.'. Please see InnerException for more details.
Source=mscorlib
Action=http://schemas.microsoft.com/net/2005/12/windowscommunicationfoundation/dispatcher/fault
StackTrace:
Server stack trace:
at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameterPart(XmlDictionaryReader reader, PartInfo part, Boolean isRequest)
at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameter(XmlDictionaryReader reader, PartInfo part, Boolean isRequest)
at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeBody(XmlDictionaryReader reader, MessageVersion version, String action, MessageDescription messageDescription, Object[] parameters, Boolean isRequest)
at System.ServiceModel.Dispatcher.OperationFormatter.DeserializeBodyContents(Message message, Object[] parameters, Boolean isRequest)
at System.ServiceModel.Dispatcher.OperationFormatter.DeserializeReply(Message message, Object[] parameters)
at System.ServiceModel.Dispatcher.ProxyOperationRuntime.AfterReply(ProxyRpc& rpc)
at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
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 ConsoleApplication4.ServiceReference1.ISymbolFileParser.GetSymbols(String filePath)
at ConsoleApplication4.ServiceReference1.SymbolFileParserClient.GetSymbols(String filePath) in C:\Users\Antonio\Desktop\SymbolFileParser\ConsoleApplication4\Service References\ServiceReference1\Reference.cs:line 371
at ConsoleApplication4.Program.Main(String[] args) in C:\Users\Antonio\Desktop\SymbolFileParser\ConsoleApplication4\Program.cs:line 18
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException: System.Runtime.Serialization.SerializationException
Message='EndElement' 'SymbolElem' from namespace 'http://schemas.datacontract.org/2004/07/SymbolFileParser.Common' is not expected. Expecting element '_x003C_BitOffset_x003E_k__BackingField'.
Source=System.Runtime.Serialization
StackTrace:
at System.Runtime.Serialization.XmlObjectSerializerReadContext.ThrowRequiredMemberMissingException(XmlReaderDelegator xmlReader, Int32 memberIndex, Int32 requiredIndex, XmlDictionaryString[] memberNames)
at ReadSymbolElemFromXml(XmlReaderDelegator , XmlObjectSerializerReadContext , XmlDictionaryString[] , XmlDictionaryString[] )
at System.Runtime.Serialization.ClassDataContract.ReadXmlValue(XmlReaderDelegator xmlReader, XmlObjectSerializerReadContext context)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.ReadDataContractValue(DataContract dataContract, XmlReaderDelegator reader)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator reader, String name, String ns, Type declaredType, DataContract& dataContract)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator xmlReader, Int32 id, RuntimeTypeHandle declaredTypeHandle, String name, String ns)
at ReadArrayOfSymbolElemFromXml(XmlReaderDelegator , XmlObjectSerializerReadContext , XmlDictionaryString , XmlDictionaryString , CollectionDataContract )
at System.Runtime.Serialization.CollectionDataContract.ReadXmlValue(XmlReaderDelegator xmlReader, XmlObjectSerializerReadContext context)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.ReadDataContractValue(DataContract dataContract, XmlReaderDelegator reader)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator reader, String name, String ns, Type declaredType, DataContract& dataContract)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator xmlReader, Type declaredType, DataContract dataContract, String name, String ns)
at System.Runtime.Serialization.DataContractSerializer.InternalReadObject(XmlReaderDelegator xmlReader, Boolean verifyObjectName, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.XmlObjectSerializer.ReadObjectHandleExceptions(XmlReaderDelegator reader, Boolean verifyObjectName, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.DataContractSerializer.ReadObject(XmlDictionaryReader reader, Boolean verifyObjectName)
at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameterPart(XmlDictionaryReader reader, PartInfo part, Boolean isRequest)
InnerException:
the problem is that the DataContractSerializer does not know how to deal with cyclic references.
You can specify the IsRefernce attribute on the parent. As described here.