C# 为什么我的WCF客户端在调用WCF服务器中引发事件的方法后超时？

我在Windows服务中托管了一个WCF服务。WCF服务中有一个方法将引发Windows服务订阅的事件。当引发事件且Windows服务捕获该事件时，Windows服务调用另一个WCF方法向所有连接的客户端发送消息。出于某种原因，当我让所有这些按此顺序发生时，会抛出一个错误：

This request operation sent to http://localhost:8731/Design_Time_Addresses/WCF/WCFService/ did not receive a reply within the configured timeout (00:00:29.9939996)....

以下是WCF服务的相关代码：

public event EventHandler<CustomEventArgs> CustomEvent;

private static readonly List<IMessageCallback> subscribers = new List<IMessageCallback>();

public void SendMessageToClients(string msgType, string message)
{
    subscribers.ForEach(delegate(IMessageCallback callback)
    {
        if (((ICommunicationObject)callback).State == CommunicationState.Opened)
        {
            callback.OnMessageReceived(msgType, message, DateTime.Now);
        }
        else
        {
            subscribers.Remove(callback);
        }
    });
}

public bool messageHost()
{
    try
    {
        if (CustomEvent != null)
            CustomEvent(null, new CustomEventArgs());
        return true;
    }
    catch
    {
        return false;
    }
}

以下是客户端配置：

  <system.serviceModel>
<bindings>
  <wsDualHttpBinding>
    <binding name="WSDualHttpBinding_IWCFService" closeTimeout="00:00:10"
      openTimeout="00:00:10" receiveTimeout="00:10:00" sendTimeout="00:00:30"
      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="Message">
        <message clientCredentialType="Windows" negotiateServiceCredential="true"
          algorithmSuite="Default" />
      </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>

以及服务配置：

<system.serviceModel>
<services>
  <service name="WCF.WCFService" behaviorConfiguration="WCFBehavior">
    <endpoint address="" binding="wsDualHttpBinding" 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="WCFBehavior">
      <serviceMetadata httpGetEnabled="true"/>
      <serviceDebug includeExceptionDetailInFaults="true" />
    </behavior>
  </serviceBehaviors>
</behaviors>

这里的症状向我暗示，可能是由于同步上下文（默认情况下WCF尊重同步上下文）而发生了死锁。含义：外部消息正在等待对上下文的访问，但它本身就是现有上下文正在等待的东西

最简单的调查方法是在工作线程上执行向外消息：

ThreadPool.QueueUserWorkItem(delegate {
    wcfObj.messageHost();
});

我相信您也可以配置WCF来改变它如何接近同步上下文，但我不记得您如何发布WCF配置：客户端、服务器这听起来很有道理。我尝试在客户端中使用您的代码，但似乎客户端在冻结之前会更进一步，然后抛出超时错误。关于同步上下文，您完全正确。我发现这个链接很好地解释了这一点：@Brian-cool-看起来像
CallbackBehavior
和
ConcurrencyMode
是我记忆中的配置开关
<system.serviceModel>
<services>
  <service name="WCF.WCFService" behaviorConfiguration="WCFBehavior">
    <endpoint address="" binding="wsDualHttpBinding" 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="WCFBehavior">
      <serviceMetadata httpGetEnabled="true"/>
      <serviceDebug includeExceptionDetailInFaults="true" />
    </behavior>
  </serviceBehaviors>
</behaviors>

ThreadPool.QueueUserWorkItem(delegate {
    wcfObj.messageHost();
});