WCF服务参考-获取"XmlException:名称不能以'<'开头字符，十六进制值0x3C".在客户端 [英] WCF Service Reference - Getting "XmlException: Name cannot begin with the '<' character, hexadecimal value 0x3C" on Client Side

问题描述

我有一个智能客户端应用程序，它通过WCF与服务器通信.数据是在客户端上创建的，然后通过服务发送以进行持久化.服务器和客户端通过共享的dll使用相同的域类，而我在Visual Studio中使用了方便的添加服务引用"功能，该功能包装了SvcUtil.exe并生成了客户端和代理类.

I have a smart client application communicating with its server via WCF. Data is created on the client and then sent over the service to be persisted. The server and client use the same domain classes via a shared dll and I'm using the handy "Add Service Reference" functionality in Visual Studio that wraps SvcUtil.exe and generates the client and proxy classes.

尝试调用服务时收到以下错误:

I get the following error when trying to call the service:

System.Xml.XmlException occurred
  Message=Name cannot begin with the '<' character, hexadecimal value 0x3C.
  Source=System.Xml
  LineNumber=0
  LinePosition=1
  StackTrace:
       at System.Xml.XmlConvert.VerifyNCName(String name, ExceptionType exceptionType)
  InnerException: 

这特别麻烦，因为该服务将一次运行数周而不会发生此错误，然后突然又无警告地再次出现.我根本无法弄清楚是什么原因造成的.当确实发生这种情况时，我将深入研究如何解决它，并且除了实际尝试以编程方式将其序列化为xml时遇到相同错误的人以外，通常不会提出更多其他建议.我只使用生成的客户端和代理来尝试发送此数据.

This is particularly troublesome because the service will work for weeks at a time without this error occurring and then suddenly and without warning it will appear again. I haven't been able to figure out what causes it at all. When it does happen, I will do a deep dive into researching how to fix it and usually don't come up with anything more than people who have experienced the same error while actually trying to serialize things to xml programmatically. I am using nothing but the generated client and proxies to try and send this data.

我在解决方案的 Service References \ AwesomeService 文件夹中查看了生成的代理，没有发现任何异常.生成的文件中唯一出现尖括号的是:

I have looked into the generated proxies in the Service References\AwesomeService folder of my solution and see nothing that looks out of the ordinary. The only occurrences of angle brackets in the generated files are:

* .svcinfo，Reference.svcmap，AwesomeService.disco，AwesomeService.wsdl和* .xsd文件中的
• xml标签
• Reference.cs文件中通用集合的参数

• xml tags in the *.svcinfo, Reference.svcmap, AwesomeService.disco, AwesomeService.wsdl and *.xsd files
• arguments to generic collections in the Reference.cs file

我用来调用该服务的代码如下:

The code I'm using to call the service is such:

using (var client = new AwesomeServiceClient())
{
    client.SaveAwesomeness(instanceOfAwesomeness);
}

这是从上面列出的调用代码上方的第一帧开始的堆栈:

This is the stack beggining with the first frame above the calling code listed above:

System.Xml.dll!System.Xml.XmlConvert.VerifyNCName(string name, System.Xml.ExceptionType exceptionType) + 0xb5 bytes 
System.Runtime.Serialization.dll!System.Runtime.Serialization.DataContract.IsValidNCName(string name) + 0x27 bytes  
System.Runtime.Serialization.dll!System.Runtime.Serialization.DataContract.EncodeLocalName(string localName) + 0x1d bytes   
System.Runtime.Serialization.dll!System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper.ImportDataMembers() + 0x2e1 bytes   
System.Runtime.Serialization.dll!System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper.ClassDataContractCriticalHelper(System.Type type) + 0x10d bytes 
System.Runtime.Serialization.dll!System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(int id, System.RuntimeTypeHandle typeHandle, System.Type type) + 0x198 bytes   
System.Runtime.Serialization.dll!System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(int id, System.RuntimeTypeHandle typeHandle, System.Type type) + 0x57 bytes 
System.Runtime.Serialization.dll!System.Runtime.Serialization.XmlObjectSerializerContext.GetDataContract(int id, System.RuntimeTypeHandle typeHandle) + 0x37 bytes  
System.Runtime.Serialization.dll!System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(System.Runtime.Serialization.XmlWriterDelegator xmlWriter, object obj, bool isDeclaredType, bool writeXsiType, int declaredTypeID, System.RuntimeTypeHandle declaredTypeHandle) + 0x49 bytes    
[Lightweight Function]  
System.Runtime.Serialization.dll!System.Runtime.Serialization.ClassDataContract.WriteXmlValue(System.Runtime.Serialization.XmlWriterDelegator xmlWriter, object obj, System.Runtime.Serialization.XmlObjectSerializerWriteContext context) + 0x25 bytes 
System.Runtime.Serialization.dll!System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(System.Runtime.Serialization.DataContract dataContract, System.Runtime.Serialization.XmlWriterDelegator xmlWriter, object obj, System.RuntimeTypeHandle declaredTypeHandle) + 0x18 bytes   
System.Runtime.Serialization.dll!System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(System.Runtime.Serialization.DataContract dataContract, System.Runtime.Serialization.XmlWriterDelegator xmlWriter, object obj, System.RuntimeTypeHandle declaredTypeHandle) + 0x49 bytes  
System.Runtime.Serialization.dll!System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(System.Runtime.Serialization.XmlWriterDelegator writer, object graph, System.Runtime.Serialization.DataContractResolver dataContractResolver) + 0xdf bytes  
System.Runtime.Serialization.dll!System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(System.Runtime.Serialization.XmlWriterDelegator writer, object graph, System.Runtime.Serialization.DataContractResolver dataContractResolver) + 0x26 bytes 
System.Runtime.Serialization.dll!System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(System.Runtime.Serialization.XmlWriterDelegator writer, object graph, System.Runtime.Serialization.DataContractResolver dataContractResolver) + 0x60 bytes    
System.Runtime.Serialization.dll!System.Runtime.Serialization.XmlObjectSerializer.WriteObject(System.Xml.XmlDictionaryWriter writer, object graph) + 0x2d bytes 
System.ServiceModel.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameterPart(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.PartInfo part, object graph) + 0x38 bytes 
System.ServiceModel.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameter(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.PartInfo part, object graph) + 0xbe bytes 
System.ServiceModel.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameters(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.PartInfo[] parts, object[] parameters) + 0x3e bytes  
System.ServiceModel.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeBody(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Channels.MessageVersion version, string action, System.ServiceModel.Description.MessageDescription messageDescription, object returnValue, object[] parameters, bool isRequest) + 0x68 bytes   
System.ServiceModel.dll!System.ServiceModel.Dispatcher.OperationFormatter.SerializeBodyContents(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Channels.MessageVersion version, object[] parameters, object returnValue, bool isRequest) + 0x7b bytes   
System.ServiceModel.dll!System.ServiceModel.Dispatcher.OperationFormatter.OperationFormatterMessage.OperationFormatterBodyWriter.OnWriteBodyContents(System.Xml.XmlDictionaryWriter writer) + 0x4f bytes    
System.ServiceModel.dll!System.ServiceModel.Channels.BodyWriter.WriteBodyContents(System.Xml.XmlDictionaryWriter writer) + 0xf8 bytes   
System.ServiceModel.dll!System.ServiceModel.Channels.BodyWriterMessage.OnBodyToString(System.Xml.XmlDictionaryWriter writer) + 0x1f bytes   
System.ServiceModel.dll!System.ServiceModel.Channels.Message.ToString(System.Xml.XmlDictionaryWriter writer) + 0xaa bytes   
System.ServiceModel.dll!System.ServiceModel.Diagnostics.MessageLogTraceRecord.WriteTo(System.Xml.XmlWriter writer) + 0x166 bytes    
System.ServiceModel.dll!System.ServiceModel.Diagnostics.MessageLogger.LogInternal(System.ServiceModel.Diagnostics.MessageLogTraceRecord record) + 0x77 bytes    
System.ServiceModel.dll!System.ServiceModel.Diagnostics.MessageLogger.LogMessageImpl(ref System.ServiceModel.Channels.Message message, System.Xml.XmlReader reader, System.ServiceModel.Diagnostics.MessageLoggingSource source) + 0x104 bytes  
System.ServiceModel.dll!System.ServiceModel.Diagnostics.MessageLogger.LogMessage(ref System.ServiceModel.Channels.Message message, System.Xml.XmlReader reader, System.ServiceModel.Diagnostics.MessageLoggingSource source) + 0x3a bytes   
System.ServiceModel.dll!System.ServiceModel.Channels.ServiceChannel.PrepareCall(System.ServiceModel.Dispatcher.ProxyOperationRuntime operation, bool oneway, ref System.ServiceModel.Dispatcher.ProxyRpc rpc) + 0x436 bytes 
System.ServiceModel.dll!System.ServiceModel.Channels.ServiceChannel.Call(string action, bool oneway, System.ServiceModel.Dispatcher.ProxyOperationRuntime operation, object[] ins, object[] outs, System.TimeSpan timeout) + 0x12b bytes    
System.ServiceModel.dll!System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(System.Runtime.Remoting.Messaging.IMethodCallMessage methodCall, System.ServiceModel.Dispatcher.ProxyOperationRuntime operation) + 0x64 bytes    
System.ServiceModel.dll!System.ServiceModel.Channels.ServiceChannelProxy.Invoke(System.Runtime.Remoting.Messaging.IMessage message) + 0x6a bytes    
mscorlib.dll!System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref System.Runtime.Remoting.Proxies.MessageData msgData, int type) + 0xee bytes

是什么原因引起的，我该如何预防?或者，也欢迎您如何进一步解决此问题?

What causes this and how do I prevent it? Or, also welcomed, how do I go about troubleshooting this further?

推荐答案

看看您的DataTables(如果这就是您用来传输数据的东西).

Have a look at your DataTables (if that's what you are using to transport data).

如果DataTable名称为空，则序列化器可能会感到困惑，并会错误地序列化某些东西.

If the DataTable name is empty, then the Serializer might get confused and serialise things incorrectly.

否则，如果您使用类型化的[Serializable]对象，我发现有时如果使用动态属性声明，则序列化程序也会感到困惑，例如:

Otherwise, if you are using typed, [Serializable] objects, I have found that sometimes the Serializer also gets confused if you use dynamic property declarations, eg:

public string MyName { get; set; }

但这将是一个容易重复的错误.

But this would be a easily repeatable error.

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