c# - System.Web.Routing.RouteCollection.GetRouteData 中的异常

Question

我在 iis7 上运行的 asp.net mvc 代码中随机出现两个异常:

Exception type: InvalidOperationException 
Exception message: Collection was modified; enumeration operation may not execute. 
   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at System.Collections.Generic.List'1.Enumerator.MoveNextRare()
   at System.Collections.Generic.List'1.Enumerator.MoveNext()
   at System.Web.Routing.RouteCollection.GetRouteData(HttpContextBase httpContext)
   at System.Web.Routing.UrlRoutingModule.PostResolveRequestCache(HttpContextBase context)
   at System.Web.Routing.UrlRoutingModule.OnApplicationPostResolveRequestCache(Object sender, EventArgs e)
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

和

Exception type: NullReferenceException 
Exception message: Object reference not set to an instance of an object. 
   at System.Web.Routing.RouteCollection.GetRouteData(HttpContextBase httpContext)
   at System.Web.Routing.UrlRoutingModule.PostResolveRequestCache(HttpContextBase context)
   at System.Web.Routing.UrlRoutingModule.OnApplicationPostResolveRequestCache(Object sender, EventArgs e)
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

它不是始终可重现的，但我认为它正在改变(或破坏)RouteTable.Routes。我在我的项目中访问 RouteTable.Routes 的唯一地方是在 Global.asax.cs 中，我知道那里的代码只被调用一次，所以这不是问题.知道如何追踪它吗？

Answer 1

在我的例子中，它最终成为一个 HttpModule:Ext.Direct.Mvc (用于 ASP.NET MVC 的 Ext.Direct)。该模块有一个错误(已在 0.8.0 版中修复)，每次为 IHttpModule 调用 Init() 时都会重新注册路由。 (which might be called multiple times)。如果时机正确，它会破坏 RouteTable.Routes 集合，并导致上述两个异常之一。