Html Helper is not detecting the model in ASP.Net mvc3

Question

In my current project i have to implement Dynamically loading tree menu from database in ASP.Net MVC3 Razor.The below structure shows my Menu Model. Level of Expertise in MVC3: Beginner

MenuId Name ParentMenuId OrderBy

1 Item1 Null 1 2 Item2 Null 2 3 Item 2.1
2 1 4 Item 2.1.1 3 1 5 Item 2.1.2 3 2

for that i have done the following things 1.Created Htmlhelper Contains static classes for Menus and sub menus, 2.Created Model for Menu, 3.added HtmlHelper namespace to views/web.config

When we debug the code it shows an error that value cannot be null.But my db contains the data ie count =11 The error is due to menu counting to Zero.So how to solve this because menu table contains 11 rows of data?

Error

Value cannot be null. Parameter name: source

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentNullException: Value cannot be null. Parameter name: source

Source Error:

Line 14: { Line 15: string htmloutput=string.Empty; Line 16: if (menu.Count() > 0) Line 17: { Line 18: htmloutput += "";

Source File: D:\VS Projects\Elixir\Elixir\HtmlHelpers\HtmlHelperExtensions.cs Line: 16

Stack Trace:

[ArgumentNullException: Value cannot be null. Parameter name: source] System.Linq.Enumerable.Count(IEnumerable1 source) +4164811
Elixir.HtmlHelpers.HtmlHelperExtensions.ParentMenus(HtmlHelper html, IEnumerable1 menu) in D:\VS Projects\Elixir\Elixir\HtmlHelpers\HtmlHelperExtensions.cs:16
ASP._Page_Views_Home_Menus_cshtml.Execute() in d:\VS Projects\Elixir\Elixir\Views\Home\Menus.cshtml:4
System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +207
System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +81
System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +88
System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +220
System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +115
System.Web.Mvc.HtmlHelper.RenderPartialInternal(String partialViewName, ViewDataDictionary viewData, Object model, TextWriter writer, ViewEngineCollection viewEngineCollection) +279
System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +113 System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName) +31
ASP._Page_Views_Home_Index_cshtml.b_2() in d:\VS Projects\Elixir\Elixir\Views\Home\Index.cshtml:16
System.Web.WebPages.<>c_DisplayClassb.b__9(TextWriter tw) +283 System.Web.WebPages.HelperResult.WriteTo(TextWriter writer) +12 System.Web.WebPages.WebPageBase.Write(HelperResult result) +67 ASP._Page_Views_Shared__LayoutUser_cshtml.Execute() in d:\VS Projects\Elixir\Elixir\Views\Shared_LayoutUser.cshtml:136
System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +207
System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +81
System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +88
System.Web.WebPages.<>c_DisplayClass7.b_6(TextWriter writer) +102 System.Web.WebPages.HelperResult.WriteTo(TextWriter writer) +12 System.Web.WebPages.WebPageBase.Write(HelperResult result) +67
System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action1 body) +66
System.Web.WebPages.WebPageBase.PopContext() +262
System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +95
System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +220
System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +115
System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +303 System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +23 System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func1 continuation) +260
System.Web.Mvc.<>c_DisplayClass1e.b_1b() +19 System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList1 filters, ActionResult actionResult) +177
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +343
System.Web.Mvc.Controller.ExecuteCore() +116
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +97 System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10
System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +37
System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21
System.Web.Mvc.Async.<>c__DisplayClass81.b__7(IAsyncResult ) +12 System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 System.Web.Mvc.<>c_DisplayClasse.b_d() +50
System.Web.Mvc.SecurityUtil.b_0(Action f) +7 System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8862381 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

HTML HELPER CODE

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Html;
using Elixir.Models;

namespace Elixir.HtmlHelpers
{
    public static class HtmlHelperExtensions
    {
        public static string ParentMenus(this HtmlHelper html,IEnumerable<Menus> menu)
        {
            string htmloutput=string.Empty;
            if (menu.Count() > 0)
            {
                htmloutput += "<ul class='side-navigation accordion' id='nav-accordion'>";
                var MainMenu = from mainMenu in menu where mainMenu.MainMenuId == null orderby mainMenu.MenuOrder select mainMenu;
                foreach(Menus m in MainMenu)
                {
                    htmloutput += "<li>";
                    htmloutput += "<li><i class='icon-home'>";
                    htmloutput += LinkExtensions.ActionLink(html, m.LinkName, m.ActionName, m.ControllerName);
                    htmloutput += "</li>";
                    htmloutput += "</li></i>";
                }
                htmloutput += "</ul>";
            }
            return htmloutput;

        }

        public static string SubMenu(this HtmlHelper html, IEnumerable<Menus> SubMenu, int MenuId)
        {
            string htmlOutput = string.Empty;
            if (SubMenu.Count() > 0)
            {
                htmlOutput += "<ul class='side-navigation accordion' id='nav-accordion'>";
                var subMenu = from SMenu in SubMenu where SMenu.MainMenuId == MenuId orderby SMenu.MenuOrder select SMenu;
                foreach (Menus m in subMenu)
                {
                    htmlOutput += "<li>";
                    htmlOutput += "<li><i class='icon-home'>";
                    htmlOutput += LinkExtensions.ActionLink(html, m.LinkName, m.ActionName, m.ControllerName);
                    htmlOutput += "</li>";
                    htmlOutput += "</li></i>";
                }
                htmlOutput += "</ul>";
            }
            return htmlOutput;
        }

    }
}

Controller Code

public ActionResult Menus()
        {
            var MMenu = ment.Menu.ToList();
            return PartialView(MMenu);
        }

Menu.cshtml ( Partial Layout)

@model IEnumerable<Elixir.Models.Menus>

<div>
    @Html.Raw(@Html.ParentMenus(Model))



    </div>

Index Page

@{
    ViewBag.Title = "Elixir ERP V1.0 Beta";
    Layout = "~/Views/Shared/_LayoutUser.cshtml";
}
<div class="main-container">
    <div class="main-wrapper">
        <div class="scroll-top">
            <a href="#" class="tip-top" title="Go Top"><i class="icon-arrow-up"></i></a>
        </div>
        <div class="left-bar merge-left">
            <!-- SEARCH BAR -->
            <!-- LEFT NAV -->
          @section leftnav{

             <div class="left-nav">
             @Html.Partial("Menus");
             </div>


          }
        </div>
    </div>
    <div class="container">
    </div>
</div>

Menu Model

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

namespace Elixir.Models
{
    [Table("tbl_Menus")]
    public class Menus
    {
        [Key]
        public int MenuId { get; set; }
        public string UserName { get; set; }
        public string MenuName { get; set; }
        public int MenuOrder { get; set; }
        public int? MainMenuId { get; set; }
        public string LinkName { get; set; }
        public string ActionName { get; set; }
        public string ControllerName { get; set; }

    }
}

Error

Answer 1

Is your Menu.cshtml supposed to be Menus.cshtml?

If so, you're calling it as a partial on this line:

@Html.Partial("Menus");

But you're not giving it a model.

Try using

@Html.Action("Menus")