将XElement类型作为WCF服务中的对象返回时出错

这是我的经营合同：

[ServiceContract]
public interface IService
{

    [OperationContract]
    object Move();

}

以下是运营合同的执行情况。我想将XElement作为对象返回，让客户端将对象转换回XElement

public object Move()
    {
        object _x;

            var xmlTree1 = new XElement("Root",
                                        new XElement("Child", 1),
                                        new XElement("Child", 2),
                                        new XElement("Child", 3),
                                        new XElement("Child", 4),
                                        new XElement("Child", 5),
                                        new XElement("Child", 6)
                );

            var xmlTree2 = new XElement("Root",
                                        from el in xmlTree1.Elements()
                                        where ((int) el >= 3 && (int) el <= 5)
                                        select el


                );

            _x = xmlTree2;

            return _x;

    }

下面是错误消息的堆栈策略：

Server stack trace: 
   at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
   at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
   at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.RequestClientReliableChannelBinder`1.OnRequest(TRequestChannel channel, Message message, TimeSpan timeout, MaskingMode maskingMode)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout, MaskingMode maskingMode)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Security.SecuritySessionClientSettings`1.SecurityRequestSessionChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs)
   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 ConsoleApplication1.ServiceReference1.IService.Move()
   at ConsoleApplication1.ServiceReference1.ServiceClient.Move() in C:\Delete\ConsoleApplication1\Service References\ServiceReference1\Reference.cs:line 128
   at ConsoleApplication1.Program.Main(String[] args) in C:\Delete\ConsoleApplication1\Program.cs:line 20
   at System.AppDomain._nExecuteAssembly(Assembly 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)
   at System.Threading.ThreadHelper.ThreadStart()

---

您要求WCF服务将.NET类型（在您的示例中为XElement）反序列化到请求客户端，然后让客户端将.NET对象类型返回值强制转换为XElement类型。WCF不支持这种反序列化，除非您通过而不是标准DataContractSerializer将其配置为.NET序列化

---

使用它有很多限制，所以一般来说这不是一个好的实践。我相信您最好直接返回XML。答案显示了如何在数据契约中处理XML。

您能否详细说明如何在配置文件中配置NetDataContractSeriliazer？在将[ServiceKnownType（typeof（XElement））]添加到OperationContract后，我得到以下错误-这是否引起了注意？将与“XElement”对应的类型添加到已知类型列表中-例如，通过使用KnownTypeAttribute属性或将其添加到传递给DataContractSerializer的已知类型列表中。我遇到的唯一示例位于WF_WCF_Samples\WCF\Basic\Contract\Data\NetDCSasDCSwithDCR\CS文件夹中的解决方案中。您还需要实现一个标准序列化程序。所有这些必需的工作都应该暂停，因为您只想在网络上移动一些XML:）您不能做的一件事是在服务契约中使用XElement类型。还记得我提到的限制吗？一个大问题是，您只能序列化实现ISerializable的类。XElement未实现该接口，因此无法使用。确定。换句话说，您的意思是，操作契约的返回类型应该实现ISerializable（以便序列化）。对于XElement，它正在实现IXmlSerializable，因此无法使用。请确认。

Server stack trace: 
   at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
   at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
   at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.RequestClientReliableChannelBinder`1.OnRequest(TRequestChannel channel, Message message, TimeSpan timeout, MaskingMode maskingMode)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout, MaskingMode maskingMode)
   at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Security.SecuritySessionClientSettings`1.SecurityRequestSessionChannel.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs)
   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 ConsoleApplication1.ServiceReference1.IService.Move()
   at ConsoleApplication1.ServiceReference1.ServiceClient.Move() in C:\Delete\ConsoleApplication1\Service References\ServiceReference1\Reference.cs:line 128
   at ConsoleApplication1.Program.Main(String[] args) in C:\Delete\ConsoleApplication1\Program.cs:line 20
   at System.AppDomain._nExecuteAssembly(Assembly 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)
   at System.Threading.ThreadHelper.ThreadStart()