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IErrorHandler.ProvideFault(Exception, MessageVersion, Message) 方法

定義

啟用建立由服務方法發生之例外狀況所傳回的自訂 FaultException<TDetail>

public:
 void ProvideFault(Exception ^ error, System::ServiceModel::Channels::MessageVersion ^ version, System::ServiceModel::Channels::Message ^ % fault);
public:
 void ProvideFault(Exception ^ exception, System::ServiceModel::Channels::MessageVersion ^ version, System::ServiceModel::Channels::Message ^ % fault);
public void ProvideFault (Exception error, System.ServiceModel.Channels.MessageVersion version, ref System.ServiceModel.Channels.Message fault);
public void ProvideFault (Exception exception, System.ServiceModel.Channels.MessageVersion version, ref System.ServiceModel.Channels.Message fault);
abstract member ProvideFault : Exception * System.ServiceModel.Channels.MessageVersion * Message -> unit
abstract member ProvideFault : Exception * System.ServiceModel.Channels.MessageVersion * Message -> unit
Public Sub ProvideFault (error As Exception, version As MessageVersion, ByRef fault As Message)
Public Sub ProvideFault (exception As Exception, version As MessageVersion, ByRef fault As Message)

參數

errorexception
Exception

在服務作業過程中擲回的 Exception 物件。

version
MessageVersion

訊息的 SOAP 版本。

fault
Message

Message 物件,這個物件會在雙工通訊模式下傳回到用戶端或服務。

範例

下列程式碼範例將示範實作 IErrorHandler 的服務,當服務方法擲回 Managed 例外狀況時,這個實作只會傳回 FaultException<TDetail> 類型的 GreetingFault

#region IErrorHandler Members
public bool HandleError(Exception error)
{
  Console.WriteLine("HandleError called.");
  // Returning true indicates you performed your behavior.
  return true;
}

// This is a trivial implementation that converts Exception to FaultException<GreetingFault>.
public void ProvideFault(
  Exception error,
  MessageVersion ver,
  ref Message msg
)
{
  Console.WriteLine("ProvideFault called. Converting Exception to GreetingFault....");
  FaultException<GreetingFault> fe
    = new FaultException<GreetingFault>(new GreetingFault(error.Message));
  MessageFault fault = fe.CreateMessageFault();
  msg = Message.CreateMessage(
    ver,
    fault,
    "http://microsoft.wcf.documentation/ISampleService/SampleMethodGreetingFaultFault"
  );
}
#endregion
#Region "IErrorHandler Members"
Public Function HandleError(ByVal [error] As Exception) As Boolean Implements IErrorHandler.HandleError
  Console.WriteLine("HandleError called.")
  ' Returning true indicates you performed your behavior.
  Return True
End Function

' This is a trivial implementation that converts Exception to FaultException<GreetingFault>.
Public Sub ProvideFault(ByVal [error] As Exception, ByVal ver As MessageVersion, ByRef msg As Message) Implements IErrorHandler.ProvideFault
  Console.WriteLine("ProvideFault called. Converting Exception to GreetingFault....")
  Dim fe As New FaultException(Of GreetingFault)(New GreetingFault([error].Message))
  Dim fault As MessageFault = fe.CreateMessageFault()
  msg = Message.CreateMessage(ver, fault, "http://microsoft.wcf.documentation/ISampleService/SampleMethodGreetingFaultFault")
End Sub
#End Region

下列程式碼範例示範如何使用服務行為,將 IErrorHandler 實作加入至 ErrorHandlers 屬性。

// This behavior modifies no binding parameters.
#region IServiceBehavior Members
public void AddBindingParameters(
  ServiceDescription description,
  ServiceHostBase serviceHostBase,
  System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints,
  System.ServiceModel.Channels.BindingParameterCollection parameters
)
{
  return;
}

// This behavior is an IErrorHandler implementation and
// must be applied to each ChannelDispatcher.
public void ApplyDispatchBehavior(ServiceDescription description, ServiceHostBase serviceHostBase)
{
  Console.WriteLine("The EnforceGreetingFaultBehavior has been applied.");
  foreach(ChannelDispatcher chanDisp in serviceHostBase.ChannelDispatchers)
  {
    chanDisp.ErrorHandlers.Add(this);
  }
}

// This behavior requires that the contract have a SOAP fault with a detail type of GreetingFault.
public void Validate(ServiceDescription description, ServiceHostBase serviceHostBase)
{
  Console.WriteLine("Validate is called.");
  foreach (ServiceEndpoint se in description.Endpoints)
  {
    // Must not examine any metadata endpoint.
    if (se.Contract.Name.Equals("IMetadataExchange")
      && se.Contract.Namespace.Equals("http://schemas.microsoft.com/2006/04/mex"))
      continue;
    foreach (OperationDescription opDesc in se.Contract.Operations)
    {
      if (opDesc.Faults.Count == 0)
        throw new InvalidOperationException(String.Format(
          "EnforceGreetingFaultBehavior requires a "
          + "FaultContractAttribute(typeof(GreetingFault)) in each operation contract.  "
          + "The \"{0}\" operation contains no FaultContractAttribute.",
          opDesc.Name)
        );
      bool gfExists = false;
      foreach (FaultDescription fault in opDesc.Faults)
      {
        if (fault.DetailType.Equals(typeof(GreetingFault)))
        {
          gfExists = true;
          continue;
        }
      }
      if (gfExists == false)
      {
        throw new InvalidOperationException(
"EnforceGreetingFaultBehavior requires a FaultContractAttribute(typeof(GreetingFault)) in an operation contract."
        );
      }
    }
  }
}
#endregion
' This behavior modifies no binding parameters.
#Region "IServiceBehavior Members"
Public Sub AddBindingParameters(ByVal description As ServiceDescription, ByVal serviceHostBase As ServiceHostBase, ByVal endpoints As System.Collections.ObjectModel.Collection(Of ServiceEndpoint), ByVal parameters As System.ServiceModel.Channels.BindingParameterCollection) Implements IServiceBehavior.AddBindingParameters
  Return
End Sub

' This behavior is an IErrorHandler implementation and 
' must be applied to each ChannelDispatcher.
Public Sub ApplyDispatchBehavior(ByVal description As ServiceDescription, ByVal serviceHostBase As ServiceHostBase) Implements IServiceBehavior.ApplyDispatchBehavior
  Console.WriteLine("The EnforceGreetingFaultBehavior has been applied.")
  For Each chanDisp As ChannelDispatcher In serviceHostBase.ChannelDispatchers
    chanDisp.ErrorHandlers.Add(Me)
  Next chanDisp
End Sub

' This behavior requires that the contract have a SOAP fault with a detail type of GreetingFault.
Public Sub Validate(ByVal description As ServiceDescription, ByVal serviceHostBase As ServiceHostBase) Implements IServiceBehavior.Validate
  Console.WriteLine("Validate is called.")
  For Each se As ServiceEndpoint In description.Endpoints
    ' Must not examine any metadata endpoint.
    If se.Contract.Name.Equals("IMetadataExchange") AndAlso se.Contract.Namespace.Equals("http://schemas.microsoft.com/2006/04/mex") Then
      Continue For
    End If
    For Each opDesc As OperationDescription In se.Contract.Operations
      If opDesc.Faults.Count = 0 Then
        Throw New InvalidOperationException(String.Format("EnforceGreetingFaultBehavior requires a " & "FaultContractAttribute(typeof(GreetingFault)) in each operation contract.  " & "The ""{0}"" operation contains no FaultContractAttribute.", opDesc.Name))
      End If
      Dim gfExists As Boolean = False
      For Each fault As FaultDescription In opDesc.Faults
        If fault.DetailType.Equals(GetType(GreetingFault)) Then
          gfExists = True
          Continue For
        End If
      Next fault
      If gfExists = False Then
        Throw New InvalidOperationException("EnforceGreetingFaultBehavior requires a FaultContractAttribute(typeof(GreetingFault)) in an operation contract.")
      End If
    Next opDesc
  Next se
End Sub
#End Region

下列程式碼範例示範如何使用應用程式組態檔,將服務設定為載入服務行為。 如需如何在組態檔中公開服務行為的詳細資訊,請參閱 IServiceBehavior

<configuration>
  <system.serviceModel>
    <services>
      <service 
        name="Microsoft.WCF.Documentation.SampleService"
        behaviorConfiguration="metaAndErrors">
        <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="metaAndErrors">
          <serviceDebug includeExceptionDetailInFaults="true"/>
          <serviceMetadata httpGetEnabled="true"/>
          <enforceGreetingFaults />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <extensions>
      <behaviorExtensions>
        <add 
          name="enforceGreetingFaults" 
          type="Microsoft.WCF.Documentation.EnforceGreetingFaultBehavior, HostApplication, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"
        />
      </behaviorExtensions>
    </extensions>
  </system.serviceModel>
</configuration>

備註

實作 ProvideFault 方法,即可建立傳回到用戶端的自訂錯誤訊息。 除非 ProvideFault WCF 執行時間將例外狀況辨識為特別嚴重,並重新擲回例外狀況本身,否則一律會針對離開作業的例外狀況呼叫 方法。 在呼叫所有 ProvideFault 實作之後,就會將錯誤訊息傳送回用戶端 (如果 fault 不是 null)。 fault如果 參數是 null 預設錯誤,則會傳送至用戶端。

注意

在使用這個方法的期間,可以從 OperationContext.RequestContext 屬性取得導致處理錯誤的傳入訊息。

注意

因為 ProvideFault 方法可從許多不同地方呼叫,所以不保證此方法會在哪一個執行緒上呼叫。 請不要依賴作業執行緒上呼叫的 ProvideFault 方法。

適用於