IDispatchMessageInspector 接口

定义

命名空间:

System.ServiceModel.Dispatcher

程序集:

System.ServiceModel.Primitives.dll

程序集:

System.ServiceModel.dll

定义一些方法，通过这些方法，可以在服务应用程序中对入站和出站应用程序消息进行自定义检查或修改。

public interface class IDispatchMessageInspector

public interface IDispatchMessageInspector

type IDispatchMessageInspector = interface

Public Interface IDispatchMessageInspector

示例

下面的代码示例演示了一个基本的 IDispatchMessageInspector，当调用它时会将字符串写入控制台。

#region IDispatchMessageInspector Members
public object AfterReceiveRequest(ref System.ServiceModel.Channels.Message request, IClientChannel channel, InstanceContext instanceContext)
{
  Console.WriteLine("IDispatchMessageInspector.AfterReceiveRequest called.");
  return null;
}

public void BeforeSendReply(ref System.ServiceModel.Channels.Message reply, object correlationState)
{
  Console.WriteLine("IDispatchMessageInspector.BeforeSendReply called.");
}
#endregion

#Region "IDispatchMessageInspector Members"
    Public Function AfterReceiveRequest(ByRef request As System.ServiceModel.Channels.Message, _
                       ByVal channel As IClientChannel, ByVal instanceContext As InstanceContext) _
                       As Object Implements IDispatchMessageInspector.AfterReceiveRequest
        Console.WriteLine("IDispatchMessageInspector.AfterReceiveRequest called.")
        Return Nothing
    End Function

    Public Sub BeforeSendReply(ByRef reply As System.ServiceModel.Channels.Message, ByVal correlationState As Object) _
    Implements IDispatchMessageInspector.BeforeSendReply
        Console.WriteLine("IDispatchMessageInspector.BeforeSendReply called.")
    End Sub
#End Region

下面的代码示例演示了向集合中添加InspectorIDispatchMessageInspector的DispatchRuntime.MessageInspectors实现IServiceBehavior。

#region IServiceBehavior Members
public void AddBindingParameters(
  ServiceDescription serviceDescription,
  ServiceHostBase serviceHostBase,
  System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints,
  BindingParameterCollection bindingParameters
)
{ return; }

public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
  foreach (ChannelDispatcher chDisp in serviceHostBase.ChannelDispatchers)
  {
    foreach (EndpointDispatcher epDisp in chDisp.Endpoints)
    {
      epDisp.DispatchRuntime.MessageInspectors.Add(new Inspector());
      foreach (DispatchOperation op in epDisp.DispatchRuntime.Operations)
        op.ParameterInspectors.Add(new Inspector());
    }
  }
}

#Region "IServiceBehavior Members"
    Public Sub AddBindingParameters(ByVal serviceDescription As ServiceDescription, _
                   ByVal serviceHostBase As ServiceHostBase, ByVal endpoints As  _
                   System.Collections.ObjectModel.Collection(Of ServiceEndpoint), _
                   ByVal bindingParameters As BindingParameterCollection) Implements IServiceBehavior.AddBindingParameters
        Return
    End Sub

    Public Sub ApplyDispatchBehavior(ByVal serviceDescription As ServiceDescription, _
                                     ByVal serviceHostBase As ServiceHostBase) Implements _
                                     IServiceBehavior.ApplyDispatchBehavior
        For Each chDisp As ChannelDispatcher In serviceHostBase.ChannelDispatchers
            For Each epDisp As EndpointDispatcher In chDisp.Endpoints
                epDisp.DispatchRuntime.MessageInspectors.Add(New Inspector())
                For Each op As DispatchOperation In epDisp.DispatchRuntime.Operations
                    op.ParameterInspectors.Add(New Inspector())
                Next op
            Next epDisp
        Next chDisp
    End Sub

下面的代码示例演示如何使用应用程序配置文件加载插入的服务InspectorIDispatchMessageInspector行为。

<configuration>
  <system.serviceModel>
    <services>
      <service 
        name="Microsoft.WCF.Documentation.SampleService"
        behaviorConfiguration="metadataSupport">
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8080/SampleService" />
          </baseAddresses>
        </host>
        <endpoint
          address=""
          binding="wsHttpBinding"
          contract="Microsoft.WCF.Documentation.ISampleService"
        />
        <endpoint
           address="mex"
           binding="mexHttpBinding"
           contract="IMetadataExchange"
        />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="metadataSupport">
          <serviceMetadata httpGetEnabled="true" httpGetUrl=""/>
          <serviceInterceptors />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <extensions>
      <behaviorExtensions>
        <add 
          name="serviceInterceptors" 
          type="Microsoft.WCF.Documentation.InspectorInserter, HostApplication, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"
        />
      </behaviorExtensions>
    </extensions>
  </system.serviceModel>
</configuration>

注解

实现 IDispatchMessageInspector 可以在将请求消息调度到操作或者将回复消息返回到调用方之前，检查或修改入站或出站应用程序消息。 在许多情况下，调用将消息发送到的操作之前，需要先截获消息。 例如，您可以记录传入的应用程序消息或根据消息头执行某种功能。

通常情况下，由一个服务行为 (System.ServiceModel.Description.IServiceBehavior)、一个终结点行为 (System.ServiceModel.Description.IEndpointBehavior) 或一个协定行为 (System.ServiceModel.Description.IContractBehavior) 来插入消息检查器。 然后，该行为将消息检查器添加到 DispatchRuntime.MessageInspectors 集合。 有关使用行为扩展运行时的详细信息，请参阅 扩展 ServiceHost 和服务模型层。

• 在接收消息之后、将消息调度到目标操作之前，AfterReceiveRequest 方法启用自定义行为。

• 在操作返回之后发送回复之前，BeforeSendReply 方法启用自定义行为。

备注

在消息调度过程中，无论操作是单向还是请求-回复，始终在相同的点调用 IDispatchMessageInspector 对象。

方法

AfterReceiveRequest(Message, IClientChannel, InstanceContext)	在已接收入站消息后将消息调度到应发送到的操作之前调用。
BeforeSendReply(Message, Object)	在操作已返回后发送回复消息之前调用。