通过配置文件让它工作没有运气，所以决定尝试通过类级别属性走更健壮的路线。如果我可以让它工作，那么它显然是一种在服务层的故障中包装异常的好方法，而无需重复大量代码。
然而，属性中的代码似乎永远不会运行 - 尽管定义属性的代码编译得很好并且被 IDE 识别。关于解决这个问题，我已经没有什么要读的了 - 只是要处理的异常就会被抛出。
我还借用并删除了在 rorys 网站上的 CodePlex 上找到的一段代码，以在不改变其功能的情况下简化此问题（删除了冗余重载）
这让我发疯......请帮忙！:D
Rory Primrose - IErrorHandlerImplementation
编码：
服务接口和实现
[ServiceContract]
public interface IService1
{
[OperationContract]
[FaultContract(typeof(FaultException))]
string GetData(int value);
}
[ErrorHandler(typeof(KnownErrorHandler))]
public class Service1 : IService1
{
public string GetData(int value)
{
throw new Exception("This exception should get handled.");
}
}
KnownErrorHandler 实现：
public class KnownErrorHandler : IErrorHandler
{
public bool HandleError(Exception error)
{
Trace.WriteLine(error.ToString());
return true;
}
public void ProvideFault(Exception error, System.ServiceModel.Channels.MessageVersion version, ref System.ServiceModel.Channels.Message fault)
{
FaultException faultException = new FaultException("Server error encountered. All details have been logged.");
MessageFault messageFault = faultException.CreateMessageFault();
fault = Message.CreateMessage(version, messageFault, faultException.Action);
}
}
属性定义——怀疑问题出在这里。我相当确定这与我使用这段代码的方式有关。
[AttributeUsage(AttributeTargets.Class)]
public sealed class ErrorHandler : Attribute, IServiceBehavior
{
public ErrorHandler(Type errorHandler)
{
if (errorHandler == null)
{throw new ArgumentNullException("errorHandler");}
Type[] errorHandlerTypes = new[] { errorHandler };
Initialize(errorHandlerTypes);
}
public void AddBindingParameters(
ServiceDescription serviceDescription,
ServiceHostBase serviceHostBase,
Collection<ServiceEndpoint> endpoints,
BindingParameterCollection bindingParameters)
{
// Nothing to do here
}
public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{
if (serviceHostBase == null)
{
throw new ArgumentNullException("serviceHostBase");
}
// Loop through each channel dispatcher
for (Int32 dispatcherIndex = 0; dispatcherIndex < serviceHostBase.ChannelDispatchers.Count; dispatcherIndex++)
{
// Get the dispatcher for this index and cast to the type we are after
ChannelDispatcher dispatcher = (ChannelDispatcher)serviceHostBase.ChannelDispatchers[dispatcherIndex];
// Loop through each error handler
for (Int32 typeIndex = 0; typeIndex < ErrorHandlerTypes.Count; typeIndex++)
{
Type errorHandlerType = ErrorHandlerTypes[typeIndex];
// Create a new error handler instance
IErrorHandler handler = (IErrorHandler)Activator.CreateInstance(errorHandlerType);
// Add the handler to the dispatcher
dispatcher.ErrorHandlers.Add(handler);
}
}
}
public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
{ }
private void Initialize(Type[] errorHandlerTypes)
{
const String ErrorHandlerTypesParameterName = "errorHandlerTypes";
if (errorHandlerTypes == null)
{
throw new ArgumentNullException(ErrorHandlerTypesParameterName);
}
if (errorHandlerTypes.Length == 0)
{
throw new ArgumentOutOfRangeException(ErrorHandlerTypesParameterName);
}
List<String> typeNames = new List<String>(errorHandlerTypes.Length);
// Loop through each item supplied
for (Int32 index = 0; index < errorHandlerTypes.Length; index++)
{
Type errorHandlerType = errorHandlerTypes[index];
// Check if the item supplied is null
if (errorHandlerType == null)
{
throw new ArgumentNullException(ErrorHandlerTypesParameterName);
}
// Check if the type doesn't define the IErrorHandler interface
if (typeof(IErrorHandler).IsAssignableFrom(errorHandlerType) == false)
{
// We can't use this type
throw new InvalidCastException();
}
String assemblyQualifiedName = errorHandlerType.AssemblyQualifiedName;
if (typeNames.Contains(assemblyQualifiedName) == false)
{
typeNames.Add(assemblyQualifiedName);
}
else
{
throw new ArgumentException(
String.Format(CultureInfo.CurrentCulture, "Duplicate ErrorType Provided", assemblyQualifiedName));
}
}
// Store the types
ErrorHandlerTypes = new ReadOnlyCollection<Type>(errorHandlerTypes);
}
/// <summary>
/// Gets the error handler types.
/// </summary>
/// <value>
/// The error handler types.
/// </value>
public ReadOnlyCollection<Type> ErrorHandlerTypes
{
get;
private set;
}
}