In this blog we illustrate how to bind a dynamic dropdown list when dropdown list is coming from a databse in MVC

See the below Example code:

We bind a dropdownList for a States where the list of states is coming from a database.
 
We make StateDataController

 public class StateDataController : Controller
    {
        string connection = ConfigurationManager.ConnectionStrings["OrgEntity"].ConnectionString;
        public ActionResult Index()
        {
            try
            {
                State obj = new State();
                using (SqlConnection conn = new SqlConnection(connection))
                {
                    conn.Open();

                    List<SelectListItem> StateList = new List<SelectListItem>();
                    var cmdState = new SqlCommand("usp_State", conn);                                           //usp_state is Stored Procedure
                    cmdState.CommandType = CommandType.StoredProcedure;
                    if (cmdState != null)
                    {
                        SqlDataReader StateReader = null;
                        StateReader = cmdState.ExecuteReader();
                        while (StateReader.Read())
                        {
                            StateList.Add(new SelectListItem { Text = StateReader["StateName"].ToString(), Value = StateReader["StateID"].ToString() });
                        }
                        obj.StateList = StateList;
                        StateReader.Close();
                    }      
              }
       }

We make a class State

public class State
    {
        public int StateID { get; set; }
        public string StateName { get; set; }
        public IEnumerable<SelectListItem> StateList { get; set; }

    }

View to display the dropdown list

@model EmployeeData.Models.State

<div>
     @Html.DropDownListFor(model => model.StateID, Model.StateList, "--Select--")                
</div>

Conclusion:-

In above example we make a connection with sql server database where data for dropdown will come then we make store procedure in sql server to get the StateList. After getting the StateList we bind the dropdown with StateList. After binding a StateList we make a view to display the dynamic binded dropdown list.