NServiceBus System.ArgumentNullException

Question

我是 NServiceBus 的新手（也是一名绿色开发人员），我被这个异常破坏了（在 NSB 控制台中，在调用处理程序之前）：

2014-02-26 14:27:10,269 [8] ERROR NServiceBus.Unicast.Transport.TransportReceiver [(null)] <(null)> -
 Failed to deserialize message with ID: b0e459fa-0ada-431c-bbee-a2de00ee2a29
 System.Runtime.Serialization.SerializationException: An error occurred while attempting to extract logical messages
 from transport message NServiceBus.TransportMessage ---> System.ArgumentNullException: Value cannot be null.
Parameter name: path
   at System.IO.Path.CheckInvalidPathChars(String path, Boolean checkAdditional)
   at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionA
ccess access, AccessControlActions control, String[] pathListOrig, Boolean check
ForDuplicates, Boolean needFullPath, Boolean copyPathList)
   at System.IO.FileSystemInfo.set_Attributes(FileAttributes value)
   at SetIsReadOnly(Object , Object )
   at NServiceBus.Serializers.XML.XmlMessageSerializer.GetObjectOfTypeFromNode(T
ype t, XmlNode node) in c:\BuildAgent\work\31f8c64a6e8a2d7c\src\NServiceBus.Core
\Serializers\XML\XmlMessageSerializer.cs:line 492
   at NServiceBus.Serializers.XML.XmlMessageSerializer.GetPropertyValue(Type typ
e, XmlNode n) in c:\BuildAgent\work\31f8c64a6e8a2d7c\src\NServiceBus.Core\Serial
izers\XML\XmlMessageSerializer.cs:line 828
   at NServiceBus.Serializers.XML.XmlMessageSerializer.GetObjectOfTypeFromNode(T
ype t, XmlNode node) in c:\BuildAgent\work\31f8c64a6e8a2d7c\src\NServiceBus.Core
\Serializers\XML\XmlMessageSerializer.cs:line 487
   at NServiceBus.Serializers.XML.XmlMessageSerializer.Process(XmlNode node, Obj
ect parent, Type nodeType) in c:\BuildAgent\work\31f8c64a6e8a2d7c\src\NServiceBu
s.Core\Serializers\XML\XmlMessageSerializer.cs:line 379
   at NServiceBus.Serializers.XML.XmlMessageSerializer.Deserialize(Stream stream
, IList`1 messageTypesToDeserialize) in c:\BuildAgent\work\31f8c64a6e8a2d7c\src\
NServiceBus.Core\Serializers\XML\XmlMessageSerializer.cs:line 359
   at NServiceBus.Unicast.Messages.ExtractLogicalMessagesBehavior.Extract(Transp
ortMessage physicalMessage) in c:\BuildAgent\work\31f8c64a6e8a2d7c\src\NServiceB
us.Core\Unicast\Messages\ExtractLogicalMessagesBehavior.cs:line 74
   at NServiceBus.Unicast.Messages.ExtractLogicalMessagesBehavior.Invoke(Receive
PhysicalMessageContext context, Action next) in c:\BuildAgent\work\31f8c64a6e8a2
d7c\src\NServiceBus.Core\Unicast\Messages\ExtractLogicalMessagesBehavior.cs:line
 52
   --- End of inner exception stack trace ---

我从免费章节中获得了 MVC 示例项目，但我无法让 pubsub 示例工作，因为“主机不支持托管多个端点。” 我在我破碎的解决方案中从事 3 个项目，只是试图让一个简单的 1-node pub 和 1-node sub 运行：

• 核心（来自 NuGet 的 NServiceBus.Interfaces 4.4.1，包含带有 IFileUploadedEvent.cs 的事件文件夹）
• FileWatcherService（来自 NuGet 的 NServiceBus.Host 4.4.1）
• FileMoverService（来自 NuGet 的 NServiceBus.Host 4.4.1）

核心\事件\IFileUploadedEvent.cs：

using NServiceBus;
using ...

namespace Core.Events
{   public interface IFileUploadedEvent : IEvent
    {   Guid EventId { get; set; }
        string Client { get; set; }
        FileInfo FileName { get; set; }
    }
}

FileWatcherService 有默认的 app.config，没有映射。 FileWatcherService.EndpointConfig.cs：

namespace FileWatcherService
{    using NServiceBus;
     public class EndpointConfig : IConfigureThisEndpoint, AsA_Publisher    {}
}

FileWatcherService.FileWatcher.cs：

using NServiceBus;
using Core.Events;
using ...

namespace FileWatcherService
{   public class FileWatcher : IWantToRunWhenBusStartsAndStops
    {   public IBus Bus { get; set; }
        public void Activate()
         { ... }
        ...Stalker, calls PublishFileUploaded
        public void PublishFileUploaded(FileInfo fileName, string clientName)
        {   Bus.Publish<IFileUploadedEvent>(evt =>
            {   evt.EventId = Guid.NewGuid();
                evt.Client = clientName;
                evt.FileName = fileName;
            });
}   }   }

FileMoverService.App.config 包含：

  <UnicastBusConfig>
    <MessageEndpointMappings>
      <add Messages="Core" Endpoint="FileWatcherService" />
    </MessageEndpointMappings>
  </UnicastBusConfig>

在 NSB 窗口中，我看到 FileMover：订阅 Core.Events.IFileUploadedEvent FileWatcher：订阅 FileMoverService@ccc 到消息类型 Core.Events.IFileUploadedEvent

FileMover 类实现了 IHandleMessages，但由于 NServiceBus 引发了第一个错误，因此代码永远无法实现。

我尝试在 EndpointConfig 中运行 Init()，但仍然遇到同样的错误。 请帮帮我！我做错了什么？

Answer 1

如果您想使用 NServiceBus 移动文件或其他 blob，请查看使用此处描述的“数据总线”功能：

http://docs.particular.net/NServiceBus/attachments-databus-sample

Answer 2

原来你不能反序列化 FileInfo 对象。所以我必须以完全不同的方式处理这个问题。