作法：檢查及修改服務中的訊息

您可實作 System.ServiceModel.Dispatcher.IDispatchMessageInspector 並將它插入服務執行階段，以檢查或修改 Windows Communication Foundation (WCF) 用戶端內傳入或傳出的訊息。 如需詳細資訊，請參閱擴充發送器。 服務上對等的功能為 System.ServiceModel.Dispatcher.IClientMessageInspector。

檢查或修改訊息

1. 實作 System.ServiceModel.Dispatcher.IDispatchMessageInspector 介面。

2. 根據您要輕鬆插入服務訊息偵測器的範圍，決定實作 System.ServiceModel.Description.IServiceBehavior、System.ServiceModel.Description.IEndpointBehaviorSystem.ServiceModel.Description.IContractBehavior或 介面。

3. 在 ICommunicationObject.Open 上呼叫 System.ServiceModel.ServiceHost 方法之前，請先插入您的行為。 如需詳細資訊，請參閱使用行為來設定與擴充執行階段。

範例

下列程式碼範例會依序顯示：

• 服務偵測器實作。

• 插入偵測器的服務行為。

• 在服務應用程式中載入及執行此行為的組態檔。

#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

#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

<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>

另請參閱

• System.ServiceModel.Dispatcher.IClientMessageInspector
• System.ServiceModel.Dispatcher.IDispatchMessageInspector
• 使用行為來設定與擴充執行階段