MVC5 Object reference not set to an instance of an

2019-03-25 08:35发布

问题:

I'm using Asp.net MVC5 and haven't encountered such this ambiguous error since 4 years working with Microsoft MVC platform! The error occurs in Manage page in default MVC5 template. here in line 26 at the _layout.cshtml file:

Line 24:     <![endif]-->
Line 25: 
Line 26:     @Scripts.Render("~/js/intf")
Line 27:     <script>
Line 28:         if (document.documentMode === 10) {

The Stack Trace says:

[NullReferenceException: Object reference not set to an instance of an object.] ASP._Page_Views_Shared__Layout_cshtml.Execute() in c:\Users\fake\Documents\Visual Studio 2013\Projects\name\name\Views\Shared_Layout.cshtml:26
System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +198
System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +104
System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +90
System.Web.WebPages.<>c__DisplayClass7.b__6(TextWriter writer) +232 System.Web.WebPages.HelperResult.WriteTo(TextWriter writer) +10 System.Web.WebPages.WebPageBase.Write(HelperResult result) +80
System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action1 body) +63
System.Web.WebPages.WebPageBase.PopContext() +267
System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +98
System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +235
System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +291 System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList
1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +56
System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +420
System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList
1 filters, ActionResult actionResult) +52
System.Web.Mvc.Async.<>c__DisplayClass28.b__19() +173 System.Web.Mvc.Async.<>c__DisplayClass1e.b__1b(IAsyncResult asyncResult) +100
System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResultBase
1.End() +49
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
System.Web.Mvc.Controller.b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +13
System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +36
System.Web.Mvc.Async.WrappedAsyncResultBase
1.End() +54
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +39 System.Web.Mvc.Controller.b__15(IAsyncResult asyncResult, Controller controller) +12
System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +28
System.Web.Mvc.Async.WrappedAsyncResultBase
1.End() +54
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +29
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
System.Web.Mvc.MvcHandler.b__4(IAsyncResult asyncResult, ProcessRequestState innerState) +21
System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +36
System.Web.Mvc.Async.WrappedAsyncResultBase
1.End() +54
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +31 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9688704 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

Edit: As you wanted the bundling code, I placed one of them here:

bundles.Add(new ScriptBundle("~/js/intf").Include(//first internal scripts
                "~/js/jquery*",
                "~/js/modernizr.js",
                "~/js/ie-prototype-polyfill.js",
                "~/js/prettyPhoto.js"));

NOTE: If I commentize the error lines (style/script bundling lines) The error will be @ViewBag.Title as the new error! I think the Razor view Engine got into trouble here, since it can't instantiate the view's codes requirements, But Why??

I know that some errors in working with Microsoft technologies aren't really related to the error that it says. Please left me your beneficial experiences. Thanks.

Update: The terse contents for ~/views/Account/Manage.cshtml file maybe useful:

@using Social.Models;
@using Microsoft.AspNet.Identity;

@{
    ViewBag.Title = "manage";
}

<div class="layout-app">

    <div class="row row-app margin-none">

        <div class="col-md-12">

            @if (ViewBag.HasLocalPassword)
            {
                 @Html.Partial("_ChangePasswordPartial")
            }
            else
            {
                 @Html.Partial("_SetPasswordPartial")
            }
        </div>
    </div>
</div>

回答1:

Since I've used the ViewBag in master layout file as a required variable to show the project pages, missing its initialization caused to show me such this error! It was one of the irrelevant errors which I've seen from Microsoft development technologies so far.



回答2:

Try to create a new javascript file in, for example, the folder Scripts in your MVC solution and call the file app.js (or anything else).

Then place the following line underneath the other @scripts.Render lines to run it.

<script src="@Scripts.Url("~/Scripts/app.js")"></script>

Otherwise add the file to a bundle.