I've got a .NET client and server that works using NetTcpBinding on Windows, with the Microsoft .NET Framework.
I want to allow running the server on Linux, using Mono 3.2.7. However, when the Microsoft .NET client tries to call a method on the Mono server, it get this error message:
Unable to contact agent 192.168.0.xx: Error in deserializing body of reply message for operation 'MyMethod'. The empty namespace requires a null or empty prefix.
The empty namespace requires a null or empty prefix.
I've hunted around but can't get any clues as to how to fix this.
* Update *
I just tried it with BasicHttpBinding instead, and again it works fine with the Microsoft .NET Framework - but it still won't work with Mono. I get a similar error to the one I get with NetTcpBinding:
Cannot redefine the namespace for prefix '' used at current element
The server gives this stack trace:
Exception Cannot redefine the namespace for prefix '' used at current element at System.Xml.XmlTextWriter.WriteEndAttribute () [0x0028e] in /home/user/mono/mono/mcs/class/System.XML/System.Xml/XmlTextWriter2.cs:995
at System.Xml.DefaultXmlWriter.WriteEndAttribute () [0x00000] in /home/user/mono/mono/mcs/class/System.XML/System.Xml/DefaultXmlWriter.cs:116
at System.Xml.XmlSimpleDictionaryWriter.WriteEndAttribute () [0x00000] in /home/user/mono/mono/mcs/class/System.Runtime.Serialization/System.Xml/XmlSimpleDictionaryWriter.cs:97
at System.Xml.XmlWriter.WriteAttributeString (System.String prefix, System.String localName, System.String ns, System.String value) [0x00025] in /home/user/mono/mono/mcs/class/System.XML/System.Xml/XmlWriter.cs:270
at System.Xml.XmlWriter.WriteAttributeString (System.String localName, System.String value) [0x00000] in /home/user/mono/mono/mcs/class/System.XML/System.Xml/XmlWriter.cs:254
at System.Xml.XmlDictionaryWriter.WriteXmlnsAttribute (System.String prefix, System.String namespaceUri) [0x00077] in /home/user/mono/mono/mcs/class/System.Runtime.Serialization/System.Xml/XmlDictionaryWriter.cs:396
at System.Runtime.Serialization.DataContractSerializer.WriteStartObject (System.Xml.XmlDictionaryWriter writer, System.Object graph) [0x0022f] in /home/user/mono/mono/mcs/class/System.Runtime.Serialization/System.Runtime.Serialization/DataContractSerializer.cs:501
at System.Runtime.Serialization.XmlObjectSerializer.WriteObject (System.Xml.XmlDictionaryWriter writer, System.Object graph) [0x00000] in /home/user/mono/mono/mcs/class/System.Runtime.Serialization/System.Runtime.Serialization/XmlObjectSerializer.cs:113
at System.ServiceModel.Dispatcher.DataContractMessagesFormatter+DataContractBodyWriter.WriteMessagePart (System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Description.MessageBodyDescription desc, System.ServiceModel.Description.MessagePartDescription partDesc, System.Object obj) [0x00049] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs:503
at System.ServiceModel.Dispatcher.DataContractMessagesFormatter+DataContractBodyWriter.OnWriteBodyContents (System.Xml.XmlDictionaryWriter writer) [0x00054] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseMessagesFormatter.cs:486
at System.ServiceModel.Channels.BodyWriter.WriteBodyContents (System.Xml.XmlDictionaryWriter writer) [0x00000] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/BodyWriter.cs:57
at System.ServiceModel.Channels.SimpleMessage.OnWriteBodyContents (System.Xml.XmlDictionaryWriter writer) [0x00000] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/MessageImpl.cs:331
at System.ServiceModel.Channels.Message.WriteBodyContents (System.Xml.XmlDictionaryWriter writer) [0x00022] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/Message.cs:183
at System.ServiceModel.Channels.Message.WriteBody (System.Xml.XmlDictionaryWriter writer) [0x0001c] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/Message.cs:168
at System.ServiceModel.Channels.Message.OnWriteMessage (System.Xml.XmlDictionaryWriter writer) [0x00065] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/Message.cs:293
at System.ServiceModel.Channels.Message.WriteMessage (System.Xml.XmlDictionaryWriter writer) [0x00026] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/Message.cs:195
at System.ServiceModel.Channels.TextMessageEncoder.WriteMessage (System.ServiceModel.Channels.Message message, System.IO.Stream stream) [0x0004a] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels/TextMessageEncoder.cs:122
at System.ServiceModel.Channels.Http.HttpRequestContext.InternalReply (System.ServiceModel.Channels.Message msg, TimeSpan timeout) [0x00034] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels.Http/HttpRequestContext.cs:139
at System.ServiceModel.Channels.Http.HttpRequestContext.Reply (System.ServiceModel.Channels.Message msg, TimeSpan timeout) [0x00000] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Channels.Http/HttpRequestContext.cs:101
at System.ServiceModel.Dispatcher.MessageProcessingContext.Reply (Boolean useTimeout) [0x00026] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/MessageProcessingContext.cs:96
at System.ServiceModel.Dispatcher.OperationInvokerHandler.Reply (System.ServiceModel.Dispatcher.MessageProcessingContext mrc, Boolean useTimeout) [0x0001d] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/OperationInvokerHandler.cs:69
at System.ServiceModel.Dispatcher.OperationInvokerHandler.ProcessRequest (System.ServiceModel.Dispatcher.MessageProcessingContext mrc) [0x00044] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/OperationInvokerHandler.cs:29
at System.ServiceModel.Dispatcher.BaseRequestProcessorHandler.ProcessRequestChain (System.ServiceModel.Dispatcher.MessageProcessingContext mrc) [0x00000] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseRequestProcessorHandler.cs:15
at System.ServiceModel.Dispatcher.BaseRequestProcessorHandler.ProcessRequestChain (System.ServiceModel.Dispatcher.MessageProcessingContext mrc) [0x00017] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseRequestProcessorHandler.cs:16
at System.ServiceModel.Dispatcher.HandlersChain.ProcessRequestChain (System.ServiceModel.Dispatcher.MessageProcessingContext mrc) [0x0000b] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseRequestProcessor.cs:72
at System.ServiceModel.Dispatcher.BaseRequestProcessor.ProcessRequest (System.ServiceModel.Dispatcher.MessageProcessingContext mrc) [0x00018] in /home/user/mono/mono/mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/BaseRequestProcessor.cs:26
It's obviously something related to serialisation, but more than that I don't know.
I've fired up Wireshark to see what the data looks like on the wire, and the HTTP POST sent to the Windows server and the Mono server look exactly the same.
There were 2 parts to getting this working (annoyingly, both of which are required only by Mono - not by Microsoft .NET):
Set IsReference to true on the DataContract attribute on classes you will send on the wire:
[DataContract(IsReference = true)]
Do not set a namespace on the DataContract attribute on those classes