In this article I will explain with an example, how to populate (bind) DropDownList from ViewBag in ASP.Net MVC Razor.
The records from the database will be populated into a Generic List collection of Model class objects and then will be saved into a ViewBag object.
Inside the View, the ViewBag object will be passed to the Html.DropDownList Helper function for populating the DropDownList in ASP.Net MVC Razor.
Note: For beginners in using ADO.Net with ASP.Net MVC, please refer my article ASP.Net MVC: ADO.Net Tutorial with example.
 
 

Database

I have made use of the following table Fruits with the schema as follows.
Populate (Bind) DropDownList from ViewBag in ASP.Net MVC
 
I have already inserted few records in the table.
Populate (Bind) DropDownList from ViewBag in ASP.Net MVC
 
Note: You can download the database table SQL by clicking the download link below.
           Download SQL file
 
 

Namespaces

You will need to import the following namespaces.
using System.Configuration;
using System.Data.SqlClient;
using System.Collections.Generic; 
 
 

Model

The Model class consists of following properties.
public class FruitModel
{
    public int FruitId { get; set; }
    public string FruitName { get; set; }
}
 
 

Controller

The Controller consists of following Action methods.

Action method for handling GET operation

Inside this Action method, the PopulateFruits method is called.
Inside the PopulateFruits method, the records from the Fruits table are fetched using DataReader and generic list collection of FruitModel class is populated.
Finally, the generic list collection of FruitModel class objects is stored into a ViewBag object.
 

Action method for handling POST operation

This Action method handles the call made from the POST function from the View.
Note: This example uses Model class object for capturing Form field values, for more details please refer my article ASP.Net MVC: Form Submit (Post) example.
 
When the Form is submitted, the posted values are captured through the Request.Form collection.
The values of FruitId and FruitName are fetched and are set into a TempData object which will be later displayed in View using JavaScript Alert Message Box.
public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        ViewBag.Fruits = PopulateFruits();
        return View();
    }
 
    [HttpPost]
    public ActionResult Submit(FormCollection formcollection)
    {
        TempData["Message"] = "Fruit Name: " + formcollection["FruitName"];
        TempData["Message"] += "\\nFruit Id: " + formcollection["FruitId"]; ;
        return RedirectToAction("Index");
    }
 
    private static List<FruitModel>PopulateFruits()
    {
        List<FruitModel> fruits = new List<FruitModel>();
        string constr = ConfigurationManager.ConnectionStrings["Constring"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            string query = " SELECT FruitName, FruitId FROM Fruits";
            using (SqlCommand cmd = new SqlCommand(query))
            {
                cmd.Connection = con;
                con.Open();
                using (SqlDataReader sdr = cmd.ExecuteReader())
                {
                    while (sdr.Read())
                    {
                        fruits.Add(new FruitModel
                        {
                            FruitName = sdr["FruitName"].ToString(),
                            FruitId = Convert.ToInt32(sdr["FruitId"])
                        });
                    }
                }
                con.Close();
            }
        }
 
        return fruits;
    }
}
 
 

View

HTML Markup

The View consists of an HTML Form which has been created using the Html.BeginForm method with the following parameters.
ActionName – Name of the Action. In this case the name is Submit.
ControllerName – Name of the Controller. In this case the name is Home.
FormMethod – It specifies the Form Method i.e. GET or POST. In this case it will be set to POST.
The Form consists of a DropDownList, a Hidden Field and a Submit Button.
The DropDownList is generated using the Html.DropDownList Helper method.
The first parameter is the Name attribute of the DropDownList.
The second parameter is the ViewBag object for populating the DropDownList i.e. its source of data.
The third parameter is the text of the Default Item of the DropDownList. If not specified there will be no default item in the DropDownList.
Finally the fourth and the last parameter allows to specify the HTML attributes such as id, class etc.
The DropDownList has been assigned a jQuery onchange event handler, when an item is selected in the DropDownList, the Text of the selected item is copied in the Hidden Field.
When the Submit Button is clicked, the Form gets submitted and the FruitId and FruitName values are sent to the Controller.
Finally the FruitId and FruitName values of the selected Fruit are displayed using JavaScript Alert Message Box.
@{
     Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    @using (Html.BeginForm("Submit", "Home", FormMethod.Post))
    {
        @Html.DropDownList("FruitId", new SelectList(ViewBag.Fruits, "FruitId", "FruitName"), "Please select", new { @id = "ddlFruits" })
        @Html.Hidden("FruitName", null, new { @id = "hfFruitName" })
        <input type="submit" value="Submit" />
    }
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
    <script type="text/javascript">
        $("body").on("change", "#ddlFruits", function () {
            $("#hfFruitName").val($(this).find("option:selected").text());
        });
    </script>
    @if (TempData["Message"] != null)
    {
        <script type="text/javascript">
            $(function () {
                alert("@TempData["Message"]");
 
            });
        </script>
    }
</body>
</html>
 
 

Screenshot

Populate (Bind) DropDownList from ViewBag in ASP.Net MVC
 
 

Downloads

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