bind a viewdata inside dropdown list

أماني مفيد

i wanna bind a viewdata inside dropdown list ,
i use this way

@Html.DropDownListFor(model => model.First().KEYWORD_NAME, ViewData["KEYWORD"] as IEnumerable, "Select Company Name", new { @class = "form-control" })

but i have this error :

System.ArgumentNullException: 'Value cannot be null.

Parameter name: source

i don't have any parameter with name source ?
i debug the project and i checked that the view data have data inside it

how i can fix it ?

3 Replies

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Mageshwaran R6y ago
Hi,
please try this code:
Controller:
Using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MCVApp.Controllers
{
      public class HomeController : Controller
      {
            public ActionResult Index()
            {
                  List Emp = new List();
                  Emp.Add( new SelectListItem { Text = "", Value = "0" });
                  Emp.Add(new SelectListItem { Text = "Akash", Value = "1" });
                  Emp.Add(new SelectListItem { Text = "Karthik", Value = "2" });
                  Emp.Add(new SelectListItem { Text = "Giri", Value = "3" });
                  Emp.Add(new SelectListItem { Text = "Risheb", Value = "4" });
                  ViewData["EmpName"] = Emp;
                  return View();
            }
      }
}
Razor Page:
@using System.Web.Mvc
@using System.Collections

@{
      ViewBag.Title = "Home Page";
}

@Html.DropDownList("EmpName",
new SelectList((IEnumerable)ViewData["EmpName"], "Value", "Text"))
Jignesh Kumar6y ago
Hi,
@Html.DropDownListFor(x => x.AProperty, new SelectList((IEnumerable)ViewData["taskStatusList"], "ValueFieldName", "TextName","Please Select"), new {@class="myClass" })
Note : ValueFieldName, TextName will be your filed name ViewData["taskStatusList"]
Sachin Singh6y ago
Please Follow the below code
@Html.DropDownListFor(x => x.AProperty, new SelectList((IEnumerable)ViewData["taskStatusList"], "Value", "Text"), new {@class="myClass" })


public ActionResult Index()
        {
               List taskStatus = new List();
                  taskStatus.Add( new SelectListItem { Text = "New", Value = "0" });
                  taskStatus.Add(new SelectListItem { Text = "InProcess", Value = "1" });
                  taskStatus.Add(new SelectListItem { Text = "OnHold", Value = "2" });
                  taskStatus.Add(new SelectListItem { Text = "Complete", Value = "3" });
                  taskStatus.Add(new SelectListItem { Text = "Closed", Value = "4" });
                  ViewData["taskStatusList"] = taskStatus;

            return View();
        }

public class TestModel
    {
        public string AProperty { get; set; }
    }