Not able to access the Viewbag items in view in MVC using Razor(CSHTML)?

Question

I'm getting the value from db and assigning values to Viewbag and passing values from controller to view.

But when i access the items of viewbag/viewdata in view to hide and unhide,it is giving null reference exception.Viewbag/Viewdata is loosing it's data in view after returning view from controller.Because of which i'm not able iterate through the foreach loop of viewbag/viewdata

I'm designing data driven controls in the view.Based on the data from the db i want to hide and unhide controls in MVC View???

Please find the code which i'm using: I'm not able to access the viewbag items in my view. If i'm doing wrong suggest me other ways.

Controller:

public ActionResult Index()
{
     objGenController.CheckTenantControl();
     var result = GetTenantData();
     return View(result);
}


public IEnumerable<TenantModel> GetTenantData()
{
     return (from t in db.Tenant.AsEnumerable()
             join c in db.Country.AsEnumerable() on t.CountryID equals c.CountryID
             join s in db.State.AsEnumerable() on t.StateID equals s.StateID
             join ct in db.City.AsEnumerable() on t.CityID equals ct.CityID
             orderby t.Name
             select new TenantModel()
             {
                  TenantID = t.TenantID,
                  Name = t.Name,
                  Address1 = t.Address1,
                  Address2 = t.Address2,
                  Address3 = t.Address3,
                  CountryID = t.CountryID,
                  StateID = t.StateID,
                  CityID = t.CityID,
                  CountryModel = c,
                  StateModel = s,
                  CityModel = ct,
             });
}

public void CheckTenantControl()
{
     var result = GetTenantControlData();
     List<string> items = new List<string>();
     foreach (var item in result)
     {
          items.Add(item.tc.ControlID.ToString());
     }
     ViewBag.TenantControl = items;
}

public IEnumerable<dynamic> GetTenantControlData()
{
     var result = (from tc in dbEntity.TenantControls.AsEnumerable()
                   where tc.TenantID == 1
                   select new { tc });

     return result;
}

View:

@model IEnumerable<Master.TenantModel>

@{
     ViewBag.Title = "Index";
}

<h2>Tenant</h2>
<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table style="border-collapse: separate; border-spacing: 15px;">
   <tr>
      @foreach (var item in ViewBag.TenantControl)
      {
          <th style="text-align: center;">
            @if (@item.TenantID== 1)
            {
               @Html.DisplayNameFor(model => model.TenantID);
            }
            else{}
          </th>    
          <th style="text-align: center;">
            @if (@item.Name == 2)
            {
               @Html.DisplayNameFor(model => model.Name)
            }
            else{}
          </th>
          <th style="text-align: center;">
            @if (@item.Address1 == 3)
            {
               @Html.DisplayNameFor(model => model.Address1)
            }
            else{}
         </th>
      //Like this i want to hide and unhide
      }
   </tr>
   </tr>
   @foreach (var item in Model)
   {
        <tr>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.TenantID)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.Name)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.Address1)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.Address2)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.Address3)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.CountryModel.Name)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.StateModel.Name)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.CityModel.Name)
            </td>
            <td style="text-align: center;">
                @Html.DisplayFor(modelItem => item.Pin)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Phone)
            </td>
            <td>
                @Html.ActionLink("Edit", "Edit", new { id = item.TenantID }) |
                @Html.ActionLink("Details", "Details", new { id = item.TenantID }) |
                @Html.ActionLink("Delete", "Delete", new { id = item.TenantID })
            </td>
        </tr>
   }
</table>

Answer 1

What is objGenController? Why are you calling that instead of calling CheckTenantControl directly? Alternately, try this:

public ActionResult Index()
{
     ViewBag.TenantControl = objGenController.CheckTenantControl();
     var result = GetTenantData();
     return View(result);
}

public List<string> CheckTenantControl()
{
     var result = GetTenantControlData();
     List<string> items = new List<string>();
     foreach (var item in result)
     {
          items.Add(item.tc.ControlID.ToString());
     }
     return items;
}

Answer 2

your items list should be like below in your controller action:

 var items=new List<TenantModel>(); 

In your View

@foreach (var item in ViewBag.TenantControl)
{
    <th style="text-align: center;">
        if (@item.TenantID== 1)
        {
            @Html.DisplayName(@item.TenantID);
        }
        else
        {

        }
    </th>
}

once you added @ for foreach then you do not need @ for if

Answer 3

try with this

@foreach (var item in ViewBag.TenantControl)
{
    <tr>
        <td style="text-align: center;">
            @Html.DisplayFor(modelItem => item.TenantID)
        </td>
        .......
    </tr>
}