CODEWITHSUNDEEP
asp.net-mvcasp.net-mvc-4asp.net-mvc-5
Nick Kahn
Nick Kahn

Reputation: 20078

ASP.NET MVC - Dropdown - There is no ViewData item of type 'IEnumerable<SelectListItem>'

MenuType definiation:

 public string Code { get; set; } 
 public string Name { get; set; }

ASP.NET MVC 5

I have searched and read before I'm posting my question here,

I'm trying to LOAD the data in the asp.net mvc dropdownlist why is that so complicated?

//controller

public class ClientController : BaseController
{
    public ActionResult Index()
    {
       List<MenuType> ctypelist = db.ContractTypes.OrderBy(x => x.TypeOfContract).ToList();

       IEnumerable<SelectListItem> list = new SelectList(ctypelist.ToList());
       ViewBag.DropDownTypeOfContract = list;
       return View();
    }

}

//html

@model myapp.Models.Client


@Html.DropDownList("Codes", (List<SelectListItem>)ViewBag.DropDownTypeOfContract , new { style = "max-width: 600px;" })%>

Upvotes: 1

Views: 2577

Answers (2)

Erik Funkenbusch
Erik Funkenbusch

Reputation: 93434

What's complicated is that you can't seem to decide which type you're using...

First you have a List<MenuType> (I assume ContractTypes is actually of type MenuType?) Then you create a SelectList, passing the List<MenuType> to it, which implies that MenuType must have at least two properties, one called Text and one called Value. If not, you will have to specify the Text and Value property names in the SelectList constructor parameters.

After that, for some reason you convert it to a IEnumerable<SelectListItem>, then you assign that to a ViewBag item and call your View. So, at this point, your ViewBag.DropDownTypeOfContract is of type IEnumerable<SelectListItem>.

Next, in your View, you for some reason define an @model depite not passing any model at all to the view. Ok.... Whatever...

So now we get to the real problem.

@Html.DropDownList("Codes", 
    (List<SelectListItem>)ViewBag.DropDownTypeOfContract , 
     new { style = "max-width: 600px;" })%>

Ok, let's ignore for a moment the fact that you have a WebForms closing code block indicator (%>) for some reason... The biggest problem here is that you're trying to cast ViewBag.DropDownTypeOfContract to a List<SelectListItem>, which is something it is not, and never was.

You converted the List<MenuType> to a SelectList which you then converted to an IEnumerable<SelectListItem>. There was never any List<SelectListItem> involved.

So, the simple fix (besides rewriting your code to be sane) is to change your cast as such:

@Html.DropDownList("Codes", 
    (IEnumerable<SelectListItem>)ViewBag.DropDownTypeOfContract, 
     new { style = "max-width: 600px;" })

EDIT:

Since your MenuType does not contain the appropriate properties, you will have to modify your SelectList as such (Which I mention above). FYI, ctypelist is already a list, no need to convert it to a list again... that's just silly.

IEnumerable<SelectListItem> list = new SelectList(ctypelist, "Code", "Name");

Upvotes: 2

Dawood Awan
Dawood Awan

Reputation: 7328

Note: I have posted this answer without knowledge of what variables your MenuType Class has. Please add to your question and I will edit this answer according to youe MenuType Class

All Dropdowns are a collection of Value and Text Pairs.

<select>
<option value=1>TEXT 1</option>
<option value=2>TEXT 2</option>
<option value=3>TEXT 3</option>
</select>

You have a list of List<MenuType>, Which values from the MenuType do you want to display in the DropDown List?

Assuming you have this as MenuType.cs

public class MenuType
{
  public int MenuTypeId {get;set;}
  public string Name {get;set;}

}

Your dropDown should be generated like this:

    public ActionResult Index()
    {
       Dictionary<int,string> ctypelist = db.ContractTypes.OrderBy(x => x.TypeOfContract).ToDictionary(s => s.MenuTypeId, s=> s.Name);


IEnumerable<SelectListItem> selectListItems = ctypelist.Select(s => new SelectListItem() { Value = s.Key.ToString(), Text = s.Value });

       ViewBag.DropDownTypeOfContract = selectListItems;
       return View();
    }

In View:

@{
var items = (IEnumerable<SelectListItem>) ViewBag.DropDownTypeOfContract;
}

    @Html.DropDownList("Codes", items , "Select Item")

Upvotes: 1

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