它适用于某些查询,但在其他查询中,我发现null引用异常.当我将源代码附加到调试时我发现了

internal void AddsqlTiming(sqlTiming stats)
        {
            Head.AddsqlTiming(stats);
        }

上面方法中的Head属性在第198行的MiniProfiler.cs中为空.任何想法为什么？

编辑：以下方法返回datacontext对象

public static EvoletDataContext Get() 
        {
            var connection = ProfiledDbConnection.Get(new sqlConnection(ConfigurationManager.ConnectionStrings["evoletworksConnectionString"].ToString()));
            //var connection = new sqlConnection(ConfigurationManager.ConnectionStrings["evoletworksConnectionString"].ToString());
            //return new EvoletDataContext(connection);
            return DataContextUtils.CreateDataContext<EvoletDataContext>(connection);
        }

以下是miniprofiler首次崩溃的查询

public sysModule GetModuleHead(string actionName)
        {
            var val =  (from mod in db.sysModules
                        where
                        mod.ModuleActionResult.ToLower().Equals(actionName.ToLowerInvariant())
                    select mod).SingleOrDefault();
            return val;


        }

有关详细信息,请参阅this question.我尝试但未能在演示项目中重现问题.

编辑2：这是堆栈跟踪：

[NullReferenceException: Object reference not set to an instance of an object.]
   MvcMiniProfiler.MiniProfiler.AddsqlTiming(sqlTiming stats) in C:\Dev\mvc-mini-profiler\MvcMiniProfiler\MiniProfiler.cs:241
   MvcMiniProfiler.sqlTiming..ctor(DbCommand command,ExecuteType type,MiniProfiler profiler) in C:\Dev\mvc-mini-profiler\MvcMiniProfiler\sqlTiming.cs:66
   MvcMiniProfiler.sqlProfiler.ExecuteStartImpl(DbCommand command,ExecuteType type) in C:\Dev\mvc-mini-profiler\MvcMiniProfiler\sqlProfiler.cs:50
   MvcMiniProfiler.sqlProfilerExtensions.ExecuteStart(sqlProfiler sqlProfiler,DbCommand command,ExecuteType type) in C:\Dev\mvc-mini-profiler\MvcMiniProfiler\sqlProfiler.cs:95
   MvcMiniProfiler.Data.ProfiledDbCommand.ExecuteDbDataReader(CommandBehavior behavior) in C:\Dev\mvc-mini-profiler\MvcMiniProfiler\Data\ProfiledDbCommand.cs:149
   System.Data.Common.DbCommand.ExecuteReader() +12
   System.Data.Linq.sqlClient.sqlProvider.Execute(Expression query,QueryInfo queryInfo,IObjectReaderFactory factory,Object[] parentArgs,Object[] userArgs,ICompiledSubQuery[] subQueries,Object lastResult) +724
   System.Data.Linq.sqlClient.sqlProvider.ExecuteAll(Expression query,QueryInfo[] queryInfos,Object[] userArguments,ICompiledSubQuery[] subQueries) +189
   System.Data.Linq.sqlClient.sqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) +659
   System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute(Expression expression) +59
   System.Linq.Queryable.SingleOrDefault(IQueryable`1 source) +265
   UserManagement.Models.FilterRepository.GetModuleHead(String actionName) in D:\Evolet\UserManagement\UserManagement\Models\FilterRepository.cs:14
   UserManagement.Models.DummyAttrib.OnAuthorization(AuthorizationContext filterContext) in D:\Evolet\UserManagement\UserManagement\Models\Filters.cs:30
   Glimpse.Net.Plumbing.GlimpseAuthorizationFilter.OnAuthorization(AuthorizationContext filterContext) +157
   System.Web.Mvc.ControllerActionInvoker.InvokeAuthorizationFilters(ControllerContext controllerContext,IList`1 filters,ActionDescriptor actionDescriptor) +149
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext,String actionName) +830
   System.Web.Mvc.Controller.ExecuteCore() +135
   System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +232
   System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +39
   System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +68
   System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +44
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +42
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +140
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult,Object tag) +54
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult,Object tag) +40
   System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +61
   System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +31
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +56
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +110
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +38
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +690
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step,Boolean& completedSynchronously) +194