System.NullReferenceException in App_Web_*.dll

问题

I am having an odd issue.

My MVC application seems to be working perfectly fine except for one view page.

The view page in question (Organization/Edit) gets a 'NullReferenceException' on every code item on the page. Whether it is Html.TextBoxFor() or HTML.AntiForgeryToken().

I have my model, view, and controller laid out here on another question that i think is related -- https://stackoverflow.com/questions/26475866/dropdownlistfor-null-reference-error

As you can see below, my model does have information inside of it. This screen capture was taken at the "Return View("Edit", model)" inside the controller.

Exception Details

- Source = App_Web_zu4jlld0
- StackTrace =    at ASP._Page_Views_Organization_Edit_vbhtml.Execute() in C:\Users\mtaylor\Projects\Check Im Here\mtaylor-branch\CheckImHere_v2\CheckImHereMVC\Views\Organization\Edit.vbhtml:line 16
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.StartPage.RunPage()
   at System.Web.WebPages.StartPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance)
   at System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer)
   at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17()
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)

View

@ModelType CheckImHereMVC.OrganizationEditViewModel

@Using Html.BeginForm("Edit", "Organization", FormMethod.Post)
 @Html.AntiForgeryToken() 'get errors here
 @Html.ValidationSummary(True) 'get errors here
 @Html.TextBoxFor(Function(model) model.organizationSub.subName, New With {.class = "span12"}) 'and errors here
End Using

One thing i notice is that if i comment out my 'textboxfor', my error will occur at the 'ValidationSummary()', if i comment out my 'ValidationSummary()', then my error will occur at 'AntiForgeryToken()'.

So it seems that the error just happens at the last possible code area.

回答1:

I found the answer to my problem here

For anyone finding this:

Try commenting out the next code line AFTER the error.

@ModelType CheckImHereMVC.OrganizationEditViewModel

@Using Html.BeginForm("Edit", "Organization", FormMethod.Post)
   @Html.AntiForgeryToken() 
   @Html.ValidationSummary(True) 
   @Html.TextBoxFor(Function(model) model.organizationSub.subName, New With {.class = "span12"})
   @Html.TextBoxFor(Function(model) model.organizationSub.subTitle, New With {.class = "span12"})
   <img src="@Url.Content(Model.img.imgPath)" alt="IMAGES"/> 'commenting out this line fixed my issue
End Using

In the case above, i would get errors on the model.organizationSub.subTitle. If i commented that line out, i would get errors on the model.organizationSub.subName line. I then found the link mentioned and commented out the line AFTER all of my TextBoxFors. That fixed my issue.

From link: "Some times compiler could not point on exact lines having specific kind of errors in razor view may be because it could not keep their line number in stack trace or somewhere. I have found this case with Null Reference Exception and when null is passed in Url.Content.

So it helps to check the next C# statement in razor view when you did not get any error on the line shown by stack trace."

来源：https://stackoverflow.com/questions/26491175/system-nullreferenceexception-in-app-web-dll

标签

asp.net-mvc

razor

nullreferenceexception