1
如果我有這樣的服務定義：我瞭解MsmqPoisonMessageException錯誤嗎？
[PoisonErrorBehavior]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall, ConcurrencyMode = ConcurrencyMode.Multiple)]
public class MsgQueue: IMsgQueue
{
public void ProcessMsg(CustomMsg msg)
{
throw new Exception("Test");
}
}
（其中ProcessMsg是傳入MSMQ的消息的註冊方法）
，我想用我的錯誤處理程序來處理異常（我拿了從MSDN代碼爲礦山模板）：
public sealed class PoisonErrorBehaviorAttribute : Attribute, IServiceBehavior
{
MsmqPoisonMessageHandler poisonErrorHandler;
public PoisonErrorBehaviorAttribute()
{
this.poisonErrorHandler = new MsmqPoisonMessageHandler();
}
void IServiceBehavior.Validate(ServiceDescription description, ServiceHostBase serviceHostBase)
{
}
void IServiceBehavior.AddBindingParameters(ServiceDescription description, ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints, BindingParameterCollection parameters)
{
}
void IServiceBehavior.ApplyDispatchBehavior(ServiceDescription description, ServiceHostBase serviceHostBase)
{
foreach (ChannelDispatcherBase channelDispatcherBase in serviceHostBase.ChannelDispatchers)
{
ChannelDispatcher channelDispatcher = channelDispatcherBase as ChannelDispatcher;
channelDispatcher.ErrorHandlers.Add(poisonErrorHandler);
}
}
}
class MsmqPoisonMessageHandler : IErrorHandler
{
public void ProvideFault(Exception error, MessageVersion version, ref System.ServiceModel.Channels.Message fault)
{
}
public bool HandleError(Exception error)
{
string test = error.GetType().ToString();
//
// The type of the exception is never MsmqPoisonMessageException !!!
//
MsmqPoisonMessageException poisonException = error as MsmqPoisonMessageException;
if (null != poisonException)
{
long lookupId = poisonException.MessageLookupId;
Console.WriteLine(" Poisoned message -message look up id = {0}", lookupId);
}
}
然後我得到了異常的類型MsmqPoisonMessageException的從來都不是問題。我希望.NET能夠神奇地將我的「新異常（」測試「）」封裝在MsmqPoisonMessageException中，但在我的錯誤處理程序中捕獲的異常總是與我拋出的異常類型相同。
我是否會誤解這整個毒訊的行爲？我想如果我的消息處理代碼引發了一個未處理的異常，那麼這個異常就會變成MsmqPoisonMessageException，否則我不會有機會在隊列中獲得msg的lookup-id。
謝謝大家。