IErrorHandler doesn't seem to be handling my errors in WCF .. any ideas?

Question

Have been reading around on IErrorHandler and want to go the config route. so, I have read the following in an attempt to implement it.

MSDN

Keyvan Nayyeri

Answer 1

Here's a full working example:

[ServiceContract]
public interface IService1
{
    [OperationContract]
    [FaultContract(typeof(MyFault))]
    string GetData(int value);
}

[DataContract]
public class MyFault
{

}

public class Service1 : IService1
{
    public string GetData(int value)
    {
        throw new Exception("error");
    }
}

public class MyErrorHandler : IErrorHandler
{
    public bool HandleError(Exception error)
    {
        return true;
    }

    public void ProvideFault(Exception error, MessageVersion version, ref Message msg)
    {
        var vfc = new MyFault();
        var fe = new FaultException<MyFault>(vfc);
        var fault = fe.CreateMessageFault();
        msg = Message.CreateMessage(version, fault, "http://ns");
    }
}

public class ErrorHandlerExtension : BehaviorExtensionElement, IServiceBehavior
{
    public override Type BehaviorType
    {
        get { return GetType(); }
    }

    protected override object CreateBehavior()
    {
        return this;
    }

    private IErrorHandler GetInstance()
    {
        return new MyErrorHandler();
    }

    void IServiceBehavior.AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {
    }

    void IServiceBehavior.ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        IErrorHandler errorHandlerInstance = GetInstance();
        foreach (ChannelDispatcher dispatcher in serviceHostBase.ChannelDispatchers)
        {
            dispatcher.ErrorHandlers.Add(errorHandlerInstance);
        }
    }

    void IServiceBehavior.Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        foreach (ServiceEndpoint endpoint in serviceDescription.Endpoints)
        {
            if (endpoint.Contract.Name.Equals("IMetadataExchange") &&
                endpoint.Contract.Namespace.Equals("http://schemas.microsoft.com/2006/04/mex"))
                continue;

            foreach (OperationDescription description in endpoint.Contract.Operations)
            {
                if (description.Faults.Count == 0)
                {
                    throw new InvalidOperationException("FaultContractAttribute not found on this method");
                }
            }
        }
    }
}

and web.config:

<system.serviceModel>
  <services>
    <service name="ToDD.Service1">
      <endpoint address=""
                binding="basicHttpBinding"
                contract="ToDD.IService1" />
    </service>
  </services>

  <behaviors>
    <serviceBehaviors>
      <behavior>
        <serviceMetadata httpGetEnabled="true"/>
        <serviceDebug includeExceptionDetailInFaults="false"/>
        <errorHandler />
      </behavior>
    </serviceBehaviors>
  </behaviors>
  <extensions>
    <behaviorExtensions>
      <add name="errorHandler"
            type="ToDD.ErrorHandlerExtension, ToDD, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
    </behaviorExtensions>
  </extensions>

</system.serviceModel>

Answer 2

You can see if the web.config is working and loading by adding a print or a breakpoint to the ApplyDispatchBehavior, and see if that gets printed/hit when the service first opens. So is it being loaded?

I'd add a print/breakpoint at ProvideFault, as well.