我收到了我们实时环境中一个罕见且间歇性的错误报告。我尝试复现此错误,但未能成功,而该错误本身也有点神秘。同时,似乎涉及Enterprise Library跟踪(我们使用的是5.0版本)-总的来说,有点麻烦。这发生在Windows Server 2008上,应用程序在 .Net Framework 4.0(WPF)上运行。
以下为错误消息和堆栈跟踪:
以下为错误消息和堆栈跟踪:
ArgumentNullException: Value cannot be null. Parameter name: category
<StackTrace>
Server stack trace:
at Microsoft.Practices.EnterpriseLibrary.Logging.LogEntry.BuildCategoriesCollection(String category)
at Microsoft.Practices.EnterpriseLibrary.Logging.Tracer.WriteTraceMessage(String message, String entryTitle, TraceEventType eventType)
at Microsoft.Practices.EnterpriseLibrary.Logging.Tracer.WriteTraceEndMessage(String entryTitle)
at Microsoft.Practices.EnterpriseLibrary.Logging.Tracer.Dispose()
at TestApplication.ViewModelTest.<UpdateUsers>d__1a.MoveNext()
Exception rethrown at [0]:
at System.Runtime.CompilerServices.AsyncVoidMethodBuilder.<SetException>b__1(Object state)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.runTryCode(Object userData)
at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
</StackTrace>
有人能解释一下可能是什么导致了这个问题吗?
编辑: 我没有修改LogEntry.BuildCategoriesCollection方法。该方法的输入参数BuildCategoriesCollection(String category)为null。
UpdateUsers方法如下:
async void UpdateUsers()
{
Processing = true;
using (traceMgr.StartTrace("Trace"))
using (var engine = new EngineClient())
{
Users = new List<UserMasterDataModel> { _blankUser };
var users = await engine.GetPossibleTagsTask(SelectedOutcomeId, _queue.SystemCd, _queue.QueueCd);
Users.AddRange(users);
}
if (SelectedUser != _blankUser)
{
// If null user selected then initialize to the case's tag, otherwise try to find the previously selected UserName
var userNameToFind = SelectedUser == null ? _details.TagTo : SelectedUser.UserName;
SelectedUser = Users.FirstOrDefault(user => user.UserName == userNameToFind) ?? _blankUser;
OnPropertyChanged("SelectedUser");
}
}
LogEntry.BuildCategoriesCollection
吗? - Daniel A. WhiteUpdateUsers
的地方添加你的ViewModelTest
代码? - Dave ZychMicrosoft.Practices.EnterpriseLibrary.Logging.LogEntry.BuildCategoriesCollection(String category)
中,所以要捕获异常。 - Security Hound