WCF IClientMessageInspector crash on serialization - wcf

Question

I use the IClientMessageInspector and it's method BeforeSendRequest, to inspect the request messages. The thing is that some of request messages has members, which members are of type object (in the real scenario thre may be in example string or some other value, which is specified in the KnownType attribute):
[DataContract(Namespace = "")]
[KnownType(typeof(SomeValueDTO))]
public class CenDTO
{
[DataMember]
public string Uri { get; set; }
[DataMember]
public object Value { get; set; }
}
Notice, that in this project the namespaces are not defined anywhere. So on the "BeforeSendRequest" I got exception. And looks like this interface uses not the same DataContractSerializer as in the real service, which hasn't such serialization errors or smth like that.
The error:
The empty string '' is not a valid name.
at System.Xml.XmlTextWriter.LookupPrefix(String ns)
at System.Xml.XmlDictionaryWriter.XmlWrappedWriter.LookupPrefix(String namespaceUri)
at System.Xml.XmlDictionaryWriter.XmlWrappedWriter.WriteXmlnsAttribute(String prefix, String namespaceUri)
at System.Xml.XmlDictionaryWriter.WriteXmlnsAttribute(String prefix, XmlDictionaryString namespaceUri)
at System.Runtime.Serialization.XmlWriterDelegator.WriteXmlnsAttribute(XmlDictionaryString ns)
at System.Runtime.Serialization.XmlWriterDelegator.WriteAttributeQualifiedName(String attrPrefix, XmlDictionaryString attrName, XmlDictionaryString attrNs, XmlDictionaryString name, XmlDictionaryString ns)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteTypeInfo(XmlWriterDelegator writer, XmlDictionaryString dataContractName, XmlDictionaryString dataContractNamespace)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteTypeInfo(XmlWriterDelegator writer, DataContract contract, DataContract declaredContract)
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 WriteCenDTOToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , ClassDataContract )
at System.Runtime.Serialization.ClassDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
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)
at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameter(XmlDictionaryWriter writer, PartInfo part, Object graph)
at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameters(XmlDictionaryWriter writer, PartInfo[] parts, Object[] parameters)
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.SerializeBodyContents(XmlDictionaryWriter writer, MessageVersion version, Object[] parameters, Object returnValue, Boolean isRequest)
at System.ServiceModel.Dispatcher.OperationFormatter.OperationFormatterMessage.OperationFormatterBodyWriter.OnWriteBodyContents(XmlDictionaryWriter writer)
at System.ServiceModel.Channels.BodyWriter.WriteBodyContents(XmlDictionaryWriter writer)
at System.ServiceModel.Channels.BodyWriterMessage.OnBodyToString(XmlDictionaryWriter writer)
at System.ServiceModel.Channels.Message.ToString(XmlDictionaryWriter writer)
at System.ServiceModel.Channels.Message.ToString()
at CID.TopicAnalyst.CIA.Test.Utils.MessageInspector.BeforeSendRequest(Message& request, IClientChannel channel) in D:\git\...\MessageInspector.cs:line 25
at System.ServiceModel.Dispatcher.ImmutableClientRuntime.BeforeSendRequest(ProxyRpc& rpc)
Implementation of "BeforeSendRequest"(The crash is on the .ToString() ):
public object BeforeSendRequest(ref Message request, IClientChannel channel)
{
if(request.Headers.Count > 0)
{
request.Headers.RemoveAt(0);
}
MessageBuffer buffer = request.CreateBufferedCopy(Int32.MaxValue);
request = buffer.CreateMessage();
var message = buffer.CreateMessage().ToString();
var resultFile = ConfigurationManager.AppSettings.GetValues("requestFile").First();
_serializer.Write(resultFile, message);
return null;
}
The testing itself is a separate solution, which uses the service's reference.
On the service imnplmentation the operation looks like this:
[ServiceContract]
public interface ISoapService
{
[OperationContract]
SomeListResponseMessage GetSomeList(SomeListRequestMessage request);
}
[MessageContract]
public class SomeListRequestMessage : BaseRequestMessage
{
...
[MessageBodyMember]
public CenDTO Cen { get; set; }
...
}
[DataContract(Namespace = "")]
[KnownType(typeof(SemValueDTO))]
public class CenDTO
{
...
[DataMember]
public object Value { get; set; }
}
Some code of the Testing Solution:
static class Program
{
static void Main(string[] args)
{
while(true)
{
var client = new SoapServiceClient("BasicHttpBinding_ISoapService");
client.Endpoint.Behaviors.Add(new InspectorBehavior());
var soapService = client.ChannelFactory.CreateChannel();
var co = new CooRequestCreator(soapService);
co.CreateAndWriteRequests();
Console.WriteLine("Press y to repeat");
var str = Console.ReadLine();
if(str != "y") break;
}
}
Constructing the request message before calling the service:
class CooRequestCreator : BaseRequestCreator<SomeListRequestMessage>
{
SemValueDTO _semaValue = new SemValueDTO
{
Key = "fb",
Label = "Guild",
Type = "org"
};
public CooRequestCreator(ISoapService soapService) : base(soapService)
{
}
protected override SomeListRequestMessage CreateMinRequest()
{
return new SomeListRequestMessage
{
Cen =
new CenDTO
{
Value = _semaValue,
},
MaxCount = 5
};
}
Maybe someone can has the same experience and can help with that?