System.ServiceModel.CommunicationException：The underlying connection was closed: The connection was closed unexpectedly

在开发WCF的过程中，发现了当请求数据量超过了一定大小的时候，就报异常：

System.ServiceModel.CommunicationException：The underlying connection was closed: The connection was closed unexpectedly

先看服务器：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="cachingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Caching.Configuration.CacheManagerSettings, Microsoft.Practices.EnterpriseLibrary.Caching, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" />
  </configSections>
  <cachingConfiguration defaultCacheManager="Session">
    <cacheManagers>
      <add name="Session" type="Microsoft.Practices.EnterpriseLibrary.Caching.CacheManager, Microsoft.Practices.EnterpriseLibrary.Caching, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" expirationPollFrequencyInSeconds="60" maximumElementsInCacheBeforeScavenging="10000" numberToRemoveWhenScavenging="10" backingStoreName="NullBackingStore" />
    </cacheManagers>
    <backingStores>
      <add type="Microsoft.Practices.EnterpriseLibrary.Caching.BackingStoreImplementations.NullBackingStore, Microsoft.Practices.EnterpriseLibrary.Caching, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="NullBackingStore" />
    </backingStores>
  </cachingConfiguration>
  <system.web>
    <compilation debug="true" targetFramework="4.0">
      <assemblies>
        <add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
      </assemblies>
    </compilation>
  </system.web>
  <system.serviceModel>
    <!--该值指示此服务是否在 ASP.NET HTTP 应用程序管道的上下文中运行-->
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
    <services>
      <service name="WmsService.Service" behaviorConfiguration="XRServiceBehavior">
        <endpoint bindingConfiguration="BasicHttpBinding" binding="basicHttpBinding" contract="WmsService.IService" />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="XRServiceBehavior">
          <serviceMetadata httpGetEnabled="true" />
          <serviceDebug httpHelpPageEnabled="false" includeExceptionDetailInFaults="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <bindings>
      <basicHttpBinding>
        <binding name="BasicHttpBinding" allowCookies="true" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647" maxBufferSize="2147483647">
          <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
          <security mode="None">
            <transport clientCredentialType="None" proxyCredentialType="None" realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true" />
  </system.webServer>
 </configuration>

再看客户端：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding name="BasicHttpBinding_IService" allowCookies="true" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647" maxBufferSize="2147483647">
          <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
          <security mode="None">
            <transport clientCredentialType="None" proxyCredentialType="None" realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
    <client>
      <endpoint address="http://localhost:3609/Service.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IService" contract="WmsService.IService" name="BasicHttpBinding_IService" />
    </client>
    </system.serviceModel>  
</configuration>

通过寻找，终于找到原因：原来是behavior在作怪：在行为节点下面有一个类dataContractSerializer，此类有一个属性MaxItemsInObjectGraph，用来控制序列化对象中允许的最大项数。默认值为 65536 字节 (64KB)，一旦数据超出了该值，则抛出通信异常。解决方法：

在服务器的的行为配置下加上<dataContractSerializer maxItemsInObjectGraph="2147483647"/>

在客户端加上节点：

 

 <behaviors>
      <endpointBehaviors>
        <behavior name="superBehavior">
          <dataContractSerializer
            maxItemsInObjectGraph="2147483647" />
        </behavior>
      </endpointBehaviors>
 </behaviors>

然后在endpoint节点上设置属性：behaviorConfiguration="superBehavior"。

测试通过。