WCF服务类中有一个返回值类型为Stream的方法   

 [ServiceContract]
    public interface  IDMADBQueryServices
    {
        [OperationContract]
        Stream GetTopic(string topicID);

    }

借口实现为：

[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
    public class DMADBQueryService:IDMADBQueryServices
    {

        public Stream GetTopic(string topicID)
        {
            return new MemoryStream();
        }
    }

配置文件为：

  <system.serviceModel>

    <bindings>
      <basicHttpBinding>
        <binding name="bind1" maxReceivedMessageSize="90000000"   transferMode="Streamed" />
      </basicHttpBinding>
    </bindings>
   
    <services>
      <service behaviorConfiguration="DMADBQueryServices.Service1Behavior"
        name="DMADBQueryServices.DMADBQueryService">
        <endpoint address="" binding="basicHttpBinding" bindingConfiguration="bind1"
          contract="DMADBQueryServices.IDMADBQueryServices" >
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"  />
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8732/Design_Time_Addresses/DMADBQueryServices/Service1/" />
          </baseAddresses>
        </host>
      </service>
    </services>
   
    <behaviors>
      <serviceBehaviors>
        <behavior name="DMADBQueryServices.Service1Behavior">
          <serviceMetadata httpGetEnabled="True"/>
          <serviceDebug includeExceptionDetailInFaults="False" />
        </behavior>
        </serviceBehaviors>
    </behaviors>

  </system.serviceModel>

现在运行服务，在WCF TEST工具中这个方法显示：

 this operation is not supported in the wcf test because it use type system.io.stream