IErrorHandler.HandleError(Exception) Metode
Definisi
Penting
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Mengaktifkan pemrosesan terkait kesalahan dan mengembalikan nilai yang menunjukkan apakah dispatcher membatalkan sesi dan konteks instans dalam kasus tertentu.
public:
bool HandleError(Exception ^ error);public bool HandleError(Exception error);abstract member HandleError : Exception -> boolPublic Function HandleError (error As Exception) As BooleanParameter
- error
- Exception
Pengecualian yang dilemparkan selama pemrosesan.
Mengembalikan
true jika Windows Communication Foundation (WCF) tidak boleh membatalkan sesi (jika ada) dan konteks instans jika konteks instans tidak ; jika tidak Single, false. Defaultnya adalah false.
Contoh
Contoh kode berikut menunjukkan layanan yang mengimplementasikan IErrorHandler yang hanya FaultException<TDetail> mengembalikan jenis GreetingFault ketika metode layanan melemparkan pengecualian terkelola.
#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
Contoh kode berikut menunjukkan cara menggunakan perilaku layanan untuk menambahkan IErrorHandler implementasi ke ErrorHandlers properti.
// 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)
{
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
Contoh kode berikut menunjukkan cara mengonfigurasi layanan untuk memuat perilaku layanan menggunakan file konfigurasi aplikasi. Untuk detail selengkapnya tentang cara mengekspos perilaku layanan dalam file konfigurasi, lihat 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>
Keterangan
HandleError Gunakan metode untuk menerapkan perilaku terkait kesalahan seperti pengelogan kesalahan, pemberitahuan sistem, mematikan aplikasi, dan sebagainya, dan mengembalikan nilai yang menentukan apakah pengecualian telah ditangani dengan tepat.
Nota
HandleError Karena metode ini dapat dipanggil dari berbagai tempat tidak ada jaminan yang dibuat tentang utas mana metode dipanggil. Jangan bergantung pada HandleError metode yang dipanggil pada utas operasi.
Semua IErrorHandler implementasi dipanggil. Secara default (ketika nilai pengembalian adalah false), jika ada pengecualian, dispatcher membatalkan sesi apa pun dan membatalkan InstanceContext jika InstanceContextMode adalah sesuatu selain Single. Pengecualian kemudian dianggap tidak tertangani dan status apa pun dianggap rusak.
Kembali true dari HandleError untuk mencegah perilaku default ini. Jika ada handler kesalahan yang true mengembalikannya, ia menginstruksikan WCF bahwa aman untuk terus menggunakan status yang terkait dengan permintaan yang gagal.
Jika tidak ada handler kesalahan yang true kembali dari HandleError metode pengecualian dianggap tidak tertangani dan respons default berlaku, berpotensi mengakibatkan System.ServiceModel.InstanceContext dibatalkan dan saluran saat berkomunikasi pada saluran sesi atau ServiceBehaviorAttribute.InstanceContextMode properti tidak diatur ke InstanceContextMode.Single.
Parameter error tidak pernah null dan berisi objek pengecualian yang dilemparkan.
