Object reference not set to an instance of an object in Html.Partial MVC when load data

Question

I have _layout.cshtml page in mvc project that call partial view with this code

@Html.Partial("_MenuForAdmin")

The code for MenuModel :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.Text;

namespace i_insurance.Models
{
    public class MenuModel
    {
        public List<string> li { get; set; }

    }
}

The code for MenuController :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

using i_insurance.Models;
using i_insurance.DataAccess;
using System.Data;

namespace i_insurance.Controllers
{
    public class MenuController : Controller
    {

        public ActionResult Index()
        {
            MenuModel model = new MenuModel();
            model.li = LoadUl();
            return View(model);
        }

        public List<string> LoadUl()
        {
            List<string> list = new List<string>();
            list.Add("Testing");
            list.Add("MCV");
            list.Add("Project");
            return list;
        }

    }
}

The code for partial view _MenuForAdmin.cshtml :

@model i_insurance.Models.MenuModel
@foreach (var item in Model.li) {
<text>
    item
</text> }

The code for Index.cshtml inside home folder :

@{
    ViewBag.Title = "Home Page";
}
@section featured {
    <section class="featured">
        <div class="content-wrapper">
            <hgroup class="title">
                <h1>@ViewBag.Title.</h1>
                <h2>@ViewBag.Message</h2>
            </hgroup>

        </div>
    </section>
}
<h3>We suggest the following:</h3>
<ol class="round">
    <li class="one">
        <h5>Getting Started</h5>
        ASP.NET MVC gives you a powerful
    </li>
</ol>

and when i run this project in browser it show "Object reference not set to an instance of an object" , here is the

Source Error:

Line 1:  @model i_insurance.Models.MenuModel
Line 2:  
Line 3:  @foreach (var item in Model.li)
Line 4:  {
Line 5:      <text>

Source File: d:\Projects\VS2012\Website\i_insurance\i_insurance\Views\Shared\_MenuForAdmin.cshtml

Line: 3

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
   ASP._Page_Views_Shared__MenuForAdmin_cshtml.Execute() in d:\Projects\VS2012\Website\i_insurance\i_insurance\Views\Shared\_MenuForAdmin.cshtml:3
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +103
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +88
   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.HtmlHelper.RenderPartialInternal(String partialViewName, ViewDataDictionary viewData, Object model, TextWriter writer, ViewEngineCollection viewEngineCollection) +277
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +91
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName) +32
   ASP._Page_Views_Home_Index_cshtml.Execute() in d:\Projects\VS2012\Website\i_insurance\i_insurance\Views\Home\Index.cshtml:24
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +103
   System.Web.WebPages.StartPage.RunPage() +17
   System.Web.WebPages.StartPage.ExecutePageHierarchy() +62
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +76
   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.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() +23
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +245
   System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +22
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +176
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +75
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +99
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +55
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +39
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +55
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +29
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +55
   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() +9634212
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

my question is why this happen ? and how to solve it ?

Welcome to Stack Overflow! Almost all cases of `NullReferenceException` are the same. Please see "[What is a NullReferenceException in .NET?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-in-net)" for some hints. — John Saunders, Jan 28 '14 at 05:19
@JohnSaunders : in my case where is the location of this root cause issue ? — Deddy H, Jan 28 '14 at 05:34
@Jeet : you sure not error ?, it's strange. I will try to create new solution and test for this — Deddy H, Jan 28 '14 at 05:35
The problem is that you are using the partial in the layout file, where you don't have access to the model. If you try to move the partial to your index.cshtml view it should work. — Håkan Fahlstedt, Jan 28 '14 at 05:35
How would I know where the issue is? You haven't included the stack trace. — John Saunders, Jan 28 '14 at 05:35
@DeddyH : ya i am sure, i just copy your code in my project then run, so its give me perfect output in partialview. I think your partialview have some issue. — Jeet Bhatt, Jan 28 '14 at 05:37
@JohnSaunders : i already included the stack trace, please help me to check it, thanks — Deddy H, Jan 28 '14 at 06:09

score 2 · Accepted Answer · answered Jan 28 '14 at 06:20

Here goes working code -

Model -

public class MenuModel
{
    public List<string> li { get; set; }

}

Controller -

public class MenuController : Controller
{
    public ActionResult IndexNew()
    {
        MenuModel model = new MenuModel();
        model.li = LoadUl();

        return PartialView("_MenuForAdmin",model);
    }

    public List<string> LoadUl()
    {
        List<string> list = new List<string>();
        list.Add("Testing");
        list.Add("MCV");
        list.Add("Project");
        return list;
    }
}

Menu IndexNew Partial View -

@model i_insurance.Models.MenuModel

@foreach (var item in Model.li)
{
    <text>
        @item
    </text> 
}

And then in your Main Index View -

@{
    Html.RenderAction("IndexNew", "Menu");
}

Finally Output -

enter image description here

yes, it work mate. thank you very much. i thing it related with the return value in controller return PartialView("_MenuForAdmin",model); — Deddy H, Jan 28 '14 at 06:48

Håkan Fahlstedt · Answer 2 · 2014-01-28T05:36:22.843

0

You should set the model of the partial in your index.cshtml view, and not using the partial in the layout file:

@Html.Partial("_MenuForAdmin", Model)

edited Jan 28 '14 at 05:36

answered Jan 28 '14 at 05:22

Håkan Fahlstedt

2,040
13
17

this is not necessary for pass model. – Jeet Bhatt Jan 28 '14 at 05:38
@Hakan : i already tried to move partial view to index.cshtml in the last position code > @Html.Partial("_MenuForAdmin",i_insurance.Models.MenuModel) but it show error in vs editor 'i_insurance.Models.MenuModel' is a 'type', which is not valid in the given context so i tried pass without model, but still have error object not reference, i include the stacktrace for that. – Deddy H Jan 28 '14 at 06:03
You should add @model i_insurance.Models.MenuModel to the top of index.cshtml and then use @Html.Partial("_MenuForAdmin", Model) or even @Html.Partial("_MenuForAdmin") as your partial will inherit the model of your view. – Håkan Fahlstedt Jan 28 '14 at 06:06
Ok, not sure what could be the problem. I saw now that you are missing an @ in the partial. It should be: `@foreach (var item in Model.li) { @item }` – Håkan Fahlstedt Jan 28 '14 at 06:20

Object reference not set to an instance of an object in Html.Partial MVC when load data

2 Answers2