IErrorHandler.HandleError(Exception) 方法

參考

定義

命名空間:: System.ServiceModel.Dispatcher

組件:: System.ServiceModel.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

啟用錯誤相關處理並傳回值，指出發送器是否會在某些情況下，中止工作階段和執行個體內容。

public:
 bool HandleError(Exception ^ error);

public:
 bool HandleError(Exception ^ exception);

public bool HandleError (Exception error);

public bool HandleError (Exception exception);

abstract member HandleError : Exception -> bool

abstract member HandleError : Exception -> bool

Public Function HandleError (error As Exception) As Boolean

Public Function HandleError (exception As Exception) As Boolean

參數

errorexception: Exception

在處理期間擲回的例外狀況。

傳回

Boolean

如果 Windows Communication Foundation (WCF) 不應中止工作階段 (如果有的話) 和執行個體內容 (如果執行個體內容不是 Single)，則為 true；否則為 false。預設為 false。

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

使用 HandleError 方法，即可實作錯誤相關行為，例如錯誤記錄、系統通知、關閉應用程式等，並傳回指定例外狀況是否已適當處理的值。

注意

因為 HandleError 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 HandleError 方法。

所有 IErrorHandler 實作都會被呼叫。根據預設， (當傳回值 false) 時，如果發生例外狀況，發送器會中止任何會話，如果 InstanceContextMode 不是 Single ，則會中止 InstanceContext 。然後例外狀況會視為未處理，而任何狀態都會視為已損毀。

從 true 傳回 HandleError，以防止這個預設行為。如果有任何錯誤處理常式傳 true 回，它會指示 WCF 安全地繼續使用與失敗要求相關聯的狀態。

如果錯誤處理常式沒有從 true 方法傳回 HandleError，則例外狀況會被視為尚未處理，而且會套用預設回應，因而可能會在工作階段通道上進行通訊時，或在 System.ServiceModel.InstanceContext 屬性未設定為 ServiceBehaviorAttribute.InstanceContextMode 時，產生中止的 InstanceContextMode.Single 和通道。

error 參數永遠不會是 null，而且會包含已擲回的例外狀況物件。

適用於

共用方式為

IErrorHandler.HandleError(Exception) 方法

定義

參數

傳回

範例

備註

適用於

其他資源