WCF 服务客户端出现“服务器未提供有意义的回复...”异常答案

【问题标题】：WCF Service client with "The server did not provide a meaningful reply..." exceptionWCF 服务客户端出现“服务器未提供有意义的回复...”异常
【发布时间】：2012-01-21 19:56:19
【问题描述】：

我有一个托管 WCF 服务的 Windows 服务。我还有一个连接到它的客户端，并且来回发送消息。当我从客户端向服务发送消息时，客户端会捕获以下异常：

服务器没有提供有意义的回复；这可能是由于合同不匹配、会话过早关闭或内部服务器错误造成的。

这有点奇怪，因为我不希望服务直接回复客户端发送的消息。服务成功获取消息，但随后客户端抛出此异常并且似乎失去了与服务的连接。

这里是服务 app.config。忽略关于 RESTfull 服务的部分：

<?xml version="1.0"?>
<configuration>
  <system.serviceModel>
    <services>
      <service name="OSAERest.api" behaviorConfiguration="MyServiceBehavior">
        <endpoint address="http://localhost:8732/api"
                  binding="webHttpBinding"
                  contract="OSAERest.IRestService"
                  behaviorConfiguration="WebHttp"/>
      </service>
      <service name="WCF.WCFService" behaviorConfiguration="WCFBehavior">
        <endpoint address="" binding="wsDualHttpBinding" bindingConfiguration="WCFBinding" contract="WCF.IWCFService">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint
          address="mex"
          binding="mexHttpBinding"
          bindingConfiguration=""
          contract="IMetadataExchange"/>
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8731/Design_Time_Addresses/WCF/WCFService/" />
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="MyServiceBehavior">
          <serviceMetadata httpGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
        <behavior name="WCFBehavior">
          <serviceMetadata httpGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="true" />
          <dataContractSerializer maxItemsInObjectGraph="2147483647" />
          <serviceTimeouts transactionTimeout="05:05:00" />
          <serviceThrottling maxConcurrentCalls="500" maxConcurrentSessions="500"
           maxConcurrentInstances="2147483647" />
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="WebHttp">
          <webHttp />
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <bindings>
      <wsDualHttpBinding>
        <binding name="WCFBinding">
          <security mode="None">
          </security>
        </binding>
      </wsDualHttpBinding>

    </bindings>
  </system.serviceModel>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
  </startup>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <probing privatePath="lib" />
    </assemblyBinding>
  </runtime>
</configuration>

这里是客户端 app.config：

<?xml version="1.0"?>
<configuration>
  <appSettings>

    <add key="ServiceIP" value="127.0.0.1"/>


  </appSettings>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
  </startup>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <probing privatePath="lib" />
    </assemblyBinding>
  </runtime>
  <system.serviceModel>
    <bindings>
      <wsDualHttpBinding>
        <binding name="WSDualHttpBinding_IWCFService" closeTimeout="00:01:00"
          clientBaseAddress="http://localhost:8733/Design_Time_Addresses/WCF/WCFService/"
          openTimeout="00:00:10" receiveTimeout="00:10:00" sendTimeout="00:00:10"
          bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
          maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text"
          textEncoding="utf-8" useDefaultWebProxy="true">
          <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
            maxBytesPerRead="4096" maxNameTableCharCount="16384" />
          <reliableSession ordered="true" inactivityTimeout="00:10:00" />
          <security mode="None">
            <message clientCredentialType="Windows" negotiateServiceCredential="true" />
          </security>
        </binding>
      </wsDualHttpBinding>
    </bindings>
    <client>
      <endpoint address="http://localhost:8731/Design_Time_Addresses/WCF/WCFService/"
        binding="wsDualHttpBinding" bindingConfiguration="WSDualHttpBinding_IWCFService"
        contract="WCFService.IWCFService" name="WSDualHttpBinding_IWCFService">
        <identity>
          <dns value="localhost" />
        </identity>
      </endpoint>
    </client>
  </system.serviceModel>
</configuration>

为什么客户端会捕捉到这个异常？

编辑：

如果有帮助，这是我将消息发送到服务的 C# 代码：

WCFServiceClient wcfObj;
EndpointAddress ep = new EndpointAddress("http://localhost:8731/Design_Time_Addresses/WCF/WCFService/");
InstanceContext context = new InstanceContext(this);
wcfObj = new Manager_WPF.WCFService.WCFServiceClient(context, "WSDualHttpBinding_IWCFService", ep);
wcfObj.Subscribe();

wcfObj.messageHost(message);

【问题讨论】：

每次客户端调用服务或发送几条消息后（或多个客户端运行时）都会发生这种情况
只连接了一个客户端。每次我向服务发送消息时都会发生这种情况。
能否出示合同，服务是否在处理请求期间尝试向客户端进行回调？
你真的需要创建一个instancecontext并将它传递给WCFServiceClient。我猜只是使用 WCFServiceClient obj = new WCFServiceClient();就足够了，因为默认情况下它会映射到客户端 app.config 中指定的关联端点，除非您有多个同名端点。
您解决了这个问题吗？

标签： c# .net wcf client-server wcf-client

【解决方案1】：

silverlight 客户端和双工 tcp 绑定也有同样的问题。该问题是由在从 wcf 方法调用返回之前调用客户端回调引起的。我已通过将回调调用放入后台线程来解决此问题：

...
ThreadPool.QueueUserWorkItem(state =>
{                   
    //this notifies service subscribers (calls registered callbacks)                               
    OnConfigurationUpdated(EventArgs.Empty); 
});
return;

【讨论】：