Question

一直在浏览IErrorHandler并希望进入配置路由。所以，我已经阅读了以下内容，试图实现它。

这基本上只是包含在继承IErrorHandler和IServiceBehaviour的类中的msdn示例...然后这包含在继承自BehaviourExtensionElement的Extension元素中，据称允许我将该元素添加到web.config中。我错过了什么？

我已经编译并从我修复的各种错误看起来像WCF实际上正在加载错误处理程序。我的问题是我在错误处理程序中处理的异常不会导致传递给它的异常。

我的服务实现只是在另一个抛出ArgumentOutOfRangeException的类上调用一个方法 - 但是这个异常永远不会被处理程序处理。

我的web.config

<system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding name="basic">
          <security mode="None" />                      
        </binding>
      </basicHttpBinding>
    </bindings>
    <extensions>
      <behaviorExtensions>
        <add name="customHttpBehavior"
             type="ErrorHandlerTest.ErrorHandlerElement, ErrorHandlerTest, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
      </behaviorExtensions>
    </extensions>
    <behaviors>
      <serviceBehaviors>
        <behavior name="exceptionHandlerBehaviour">          
          <serviceMetadata httpGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="true"/>
          <customHttpBehavior />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <services>
      <service behaviorConfiguration="exceptionHandlerBehaviour" name="ErrorHandlerTest.Service1">
        <endpoint binding="basicHttpBinding" bindingConfiguration="basic" contract="ErrorHandlerTest.IService1" />
      </service>
    </services>

服务合同

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

ErrorHandler类

public class ErrorHandler : IErrorHandler , IServiceBehavior 
{
    public bool HandleError(Exception error)
    {
        Console.WriteLine("caught exception {0}:",error.Message );
        return true;
    }

    public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
    {
       if (fault!=null )
       {
           if (error is ArgumentOutOfRangeException )
           {
               var fe = new FaultException<GeneralInternalFault>(new GeneralInternalFault("general internal fault."));
               MessageFault mf = fe.CreateMessageFault();

               fault = Message.CreateMessage(version, mf, fe.Action);

           }
           else
           {
               var fe = new FaultException<GeneralInternalFault>(new GeneralInternalFault(" the other general internal fault."));
               MessageFault mf = fe.CreateMessageFault();

               fault = Message.CreateMessage(version, mf, fe.Action);
           }
       }
    }

    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {

    }

    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        IErrorHandler errorHandler = new ErrorHandler();
        foreach (ChannelDispatcherBase channelDispatcherBase in serviceHostBase.ChannelDispatchers)
        {
            ChannelDispatcher channelDispatcher = channelDispatcherBase as ChannelDispatcher;
            if (channelDispatcher != null)
            {
                channelDispatcher.ErrorHandlers.Add(errorHandler);
            }
        }
    }


    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {


    }
}

行为扩展元素

    public class ErrorHandlerElement : BehaviorExtensionElement 
    {
        protected override object CreateBehavior()
        {
            return new ErrorHandler();
        }

        public override Type BehaviorType
        {
            get { return typeof(ErrorHandler); }
        }
    }

Answer 1

这是一个完整的工作示例：

[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");
                }
            }
        }
    }
}

和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

您可以通过向ApplyDispatchBehavior添加打印或断点来查看web.config是否正常工作并加载，并查看在服务首次打开时是否打印/点击。它被装载了吗？

我也会在ProvideFault上添加一个打印/断点。

IErrorHandler似乎没有处理我在WCF中的错误..任何想法？

2 个答案: