c# - 异常上的 JsonConvert.SerializeObject 丢失消息

Question

以前从未见过，基本上我的 MSMQ 调用抛出访问被拒绝，在 Visual Studio 中显示为( exception.ToString())

System.Messaging.MessageQueueException (0x80004005): Access to Message Queuing system is denied.\r\n at System.Messaging.MessageQueue.MQCacheableInfo.get_WriteHandle()\r\n
at System.Messaging.MessageQueue.StaleSafeSendMessage(MQPROPS properties, IntPtr transaction)\r\n at System.Messaging.MessageQueue.SendInternal(Object obj, MessageQueueTransaction internalTransaction, MessageQueueTransactionType transactionType)\r\n at redacted.d__2.MoveNext() in c:\path\file.cs:line 24

现在，这会记录到对包含我的日志记录代码的类库的调用中。

我的代码这样做:

var logMessage = new LogEntry(applicationName, exception, message, level);

LogEntry只是一个简单的老类，将这些东西放入属性中，不做任何其他事情。
var logEntryAsJson = JsonConvert.SerializeObject(logMessage);
此行应将其序列化为 JSON。但是，当它发生时，异常属性更改为:

"Exception":{"NativeErrorCode":-1072824283,"ClassName":"System.Messaging.MessageQueueException","Message":"External component has thrown an exception.","Data":null,"InnerException":null,"HelpURL":null,"StackTraceString":" at System.Messaging.MessageQueue.MQCacheableInfo.get_WriteHandle()\r\n at System.Messaging.MessageQueue.StaleSafeSendMessage(MQPROPS properties, IntPtr transaction)\r\n at System.Messaging.MessageQueue.SendInternal(Object obj, MessageQueueTransaction internalTransaction, MessageQueueTransactionType transactionType)\r\n at redacted.d__2.MoveNext() in c:\path\file.cs:line 24","RemoteStackTraceString":null,"RemoteStackIndex":0,"ExceptionMethod":"8\nget_WriteHandle\nSystem.Messaging, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a\nSystem.Messaging.MessageQueue+MQCacheableInfo\nSystem.Messaging.Interop.MessageQueueHandle get_WriteHandle()","HResult":-2147467259,"Source":"System.Messaging","WatsonBuckets":null}

将鼠标悬停在序列化行上的 logMessage 对象上的智能感知显示第一个异常数据。但是当序列化时，它完全改变了它。结果，错误的原因没有被记录下来，所以我在尝试调试它的时候挠了挠头。

这种行为有原因吗？我是否必须强制将异常存储为字符串？

Answer 1

Exception类实现 ISerializable。 Json.NET recognizes this and only serializes the properties specified by the class itself .正如文档解释的那样:

ISerializable

Types that implement ISerializable and are marked with SerializableAttribute are serialized as JSON objects. When serializing, only the values returned from ISerializable.GetObjectData are used; members on the type are ignored. When deserializing, the constructor with a SerializationInfo and StreamingContext is called, passing the JSON object's values.

In situations where this behavior is not wanted, the JsonObjectAttribute can be placed on a .NET type that implements ISerializable to force it to be serialized as a normal JSON object.

MessageQueueException.Message属性在运行时计算并从 .NET 运行时的资源加载一个字符串。 It's not saved by GetObjectData因为实际文本既不需要也不想要 - 在另一个系统上反序列化时， Message将返回可用于该系统的本地化字符串。 External component has thrown an exception来自父级 ExternalException类，将字符串存储在 Message 中但不会覆盖 GetObjectData .
这对于序列化和反序列化来说不是问题，因为数据足以再水合正确的对象。不过，这是 JSON 的一个问题，它不包含类型信息。
可以禁用此行为。一种方法是向类添加属性，这在 BCL 类中是不可能的。另一种可能性是使用 Contract Resolver忽略 ISerializable。 DefaultContractResolver 具有类似 IgnoreSerializableInterface 的属性为了这 :

string json =
    JsonConvert.SerializeObject(
        exception,
        Formatting.Indented,
        new JsonSerializerSettings { 
             ContractResolver = new DefaultContractRresolver {
                   IgnoreSerializableInterface=true
        }}
    );