Bind data from database to DropDownListFor in asp.net mvc 2.0 - asp.net-mvc-2

Question

I am a new in asp.net mvc 2.0, I tried to search about this article but still can not get the answer like what I want.
I have one form to assign the role to each employee. So I create one form that I can input the employee's name and select the role that they are in. The role are taking from table Role. I used linq to sql to query the RoleName and RoleID from table Role, and want to bind it to DropDownListFor in my view.
I have one model :
public class UserModels
{
public string name { get; set; }
public string role { get; set; }
}
This is what I did in my controller :
[HttpPost]
public ActionResult UserMaintenance(FormCollection frm)
{
if (ModelState.IsValid)
{
EMP_DBSEntities context = new EMP_DBSEntities();
tblUserLogin user = new tblUserLogin();
user.UserName = frm["userLogin"].ToString();
IEnumerable<SelectListItem> role_list = context.tblRoles.Select(d => new SelectListItem
{
Value = d.RoleID.ToString(),
Text = d.RoleName
});
context.AddTotblUserLogins(user);
context.SaveChanges();
return View();
}
else
{
return View();
}
}
Can anyone tell me how could I bind the role_list to my DropDownListFor<> in my view.
Thanks.

Answer 1

In order to create a drop down list you need a view model with 2 properties: a scalar property that will contain the selected value and a collection property that will contain the available options.
So as always in ASP.NET MVC start by writing a view model:
public class UserRoleViewModel
{
[DisplayName("name")]
public string EmployeeName { get; set; }
[DisplayName("role")]
public int? SelectedRoleId { get; set; }
public IEnumerable<SelectListItem> Roles { get; set; }
}
then a controller:
public class HomeController : Controller
{
public ActionResult Index()
{
// fetch the roles
// could come from a database or something
var roles = new[]
{
new { RoleID = 1, RoleName = "Admin" },
new { RoleID = 2, RoleName = "Foo" },
new { RoleID = 3, RoleName = "Bar" },
new { RoleID = 4, RoleName = "Baz" },
};
// Now we build the model
var model = new UserRoleViewModel
{
EmployeeName = "John", // could come from a database or something
SelectedRoleId = 1, // could come from a database or something
Roles = new SelectList(roles, "RoleID", "RoleName")
};
return View(model);
}
[HttpPost]
public ActionResult Index(UserRoleViewModel model)
{
return Content(
string.Format(
"Selected role for {0} is {1}", model.EmployeeName, model.SelectedRoleId
)
);
}
}
and finally a view:
<%# Page
Language="C#"
MasterPageFile="~/Views/Shared/Site.Master"
Inherits="System.Web.Mvc.ViewPage<UserRoleViewModel>"
%>
...
<% using (Html.BeginForm()) { %>
<%= Html.EditorFor(x => x.EmployeeName) %>
<%= Html.DropDownListFor(x => x.SelectedRoleId, Model.Roles, "-- Role --") %>
<button type="submit">OK</button>
<% } %>