Question

我正在使用NServiceBus 3，当我收到消息时，我从接收端点收到此错误。：

NServiceBus.Unicast.Transport.Transactional.TransactionalTransport [(null)] <(null)> - Failed raising 'transport message received' event for message with ID=97d0f2fa-6227-439b-ad37-a304bd2af000\10428
System.NullReferenceException: Object reference not set to an instance of an object.
   at NServiceBus.MessageHeaders.MessageHeaderManager.GetHeader(Object message, String key)
   at NServiceBus.MessageHeaders.Bootstrapper.<Run>b__0(Object msg, String key)
   at NServiceBus.ExtensionMethods.GetHeader(Object msg, String key)
   at NServiceBus.ExtensionMethods.GetOriginatingSiteHeader(Object msg)
   at NServiceBus.Gateway.HeaderManagement.GatewayHeaderManager.MutateIncoming(Object message)
   at NServiceBus.Unicast.UnicastBus.<>c__DisplayClass25.<ApplyIncomingMessageMutatorsTo>b__24(IMutateIncomingMessages m)
   at System.Collections.Generic.List`1.ForEach(Action`1 action)
   at NServiceBus.Unicast.UnicastBus.ApplyIncomingMessageMutatorsTo(IBuilder builder, Object originalMessage)
   at NServiceBus.Unicast.UnicastBus.<>c__DisplayClass22.<HandleMessage>b__21(Object msg)
   at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at NServiceBus.Unicast.UnicastBus.HandleMessage(IBuilder builder, TransportMessage m)
   at NServiceBus.Unicast.UnicastBus.HandleTransportMessage(IBuilder childBuilder, TransportMessage msg)
   at NServiceBus.Unicast.UnicastBus.TransportMessageReceived(Object sender, TransportMessageReceivedEventArgs e)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at NServiceBus.Unicast.Transport.Transactional.TransactionalTransport.OnTransportMessageReceived(TransportMessage msg)

消息本身如下：

public interface ILinkPersonMessage : IBaseMessage
{
    int PersonId { get; set; }
    List<int> UnitIds { get; set; }
}

public interface IBaseMessage
{
    int UserId { get; set; }
}

在发送课程中，我这样做：

var message = bus.CreateInstance<ILinkPersonMessage>();
message.UserId = currentUser.UserId;
message.PersonId = personId;
message.UnitIds = selectedUnits;

bus.Send(message);

更新

我正在查看NServiceBus代码，这是抛出错误的方法：

    public string GetHeader(object message, string key)
    {
        if (message == ExtensionMethods.CurrentMessageBeingHandled)
            if (bus.CurrentMessageContext.Headers.ContainsKey(key))
                return bus.CurrentMessageContext.Headers[key];
            else
                return null;

        if (messageHeaders == null)
            return null;

        if (!messageHeaders.ContainsKey(message))
            return null;

        if (messageHeaders[message].ContainsKey(key))
            return messageHeaders[message][key];

        return null;
    }

通过查看该代码，只有在bus.CurrentMessageContext或bus.CurrentMessageContext.Headers为空，或者messageHeaders[message]存在但包含空值时才会发生这种情况。不幸的是，我还没有弄清楚这些场景中哪一个更有可能（甚至可能）

更新2

所以使用QueueExplorer我已经把标题拉出来了：

<?xml version="1.0"?>
<ArrayOfHeaderInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <HeaderInfo>
        <Key>NServiceBus.Version</Key>
        <Value>3.0.3</Value>
    </HeaderInfo>
    <HeaderInfo>
        <Key>NServiceBus.TimeSent</Key>
        <Value>2012-05-08 06:57:15:691208 Z</Value>
    </HeaderInfo>
    <HeaderInfo>
        <Key>NServiceBus.EnclosedMessageTypes</Key>
        <Value>Namespace.Service.ILinkPersonMessage __impl, NServiceBus.Unicast.Transport__impl, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null;Namespace.Service.ILinkPersonMessage, Namespace.Service, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null</Value>
    </HeaderInfo>
    <HeaderInfo>
        <Key>WinIdName</Key>
        <Value>*{myusername}*</Value>
    </HeaderInfo>
    <HeaderInfo>
        <Key>CorrId</Key>
    </HeaderInfo>
</ArrayOfHeaderInfo>

更新3

这是现在有效的流畅配置：

Configure.With()
.DefiningEventsAs(t => t.Namespace != null && t.Namespace.StartsWith("Events"))
.DefiningCommandsAs(t => t.Namespace != null && t.Namespace.StartsWith("Messages"))
.CastleWindsorBuilder(container)
.XmlSerializer()
.MsmqTransport()
.IsTransactional(true)
.IsolationLevel(IsolationLevel.ReadUncommitted)
.UnicastBus()
.RavenSagaPersister()
.RavenSubscriptionStorage()
.UseRavenTimeoutPersister()
.RunTimeoutManager()
.ForInstallationOn<NServiceBus.Installation.Environments.Windows>().Install();

（我已经修剪了所有命名空间）

Answer 1

这是在发送进程启动后的第一条消息上发生的，还是只发生在后续消息上？

您是否多次配置发送总线？（NServiceBus.Configure？）

Answer 2

我们最近修复了标头管理方面的一些错误，因此可能就是您遇到的问题。请尝试升级到3.0.4并查看是否能解决您的问题。

Answer 3

同样的事情发生在我身上，问题是我在配置服务总线时忘了设置xmlserialization

var configBus = NServiceBus.Configure.With()
.DefaultBuilder()
.MsmqSubscriptionStorage()
.XmlSerializer() // <== This line here
.MsmqTransport()
    .IsTransactional(true)
    .PurgeOnStartup(false)
.UnicastBus()
.ImpersonateSender(true);

我在使用NserviceBus主机接收消息时在MessageHeaderManager.GetHeader中收到NullReferenceException

3 个答案: