Reputation: 73
So I have these two tables - products, measurement_unit.
Products: (id int, name varchar(20) , id_um INT ) where id_um is a reference to the primary key of the measurement_unit table and id is the primary key of this table.
Measurement_unit: (id_um int, name varchar(20)). id_um is the primary key I mapped the two using LINQ to SQL.
When I want to create a new product I need to choose from a list of unit measurement, meaning a dropdownlist with their names but i want to bind the id for the selected one....
I'm doing this in the controller for the Create action (create a new product):
var items = new List<SelectListItem>();
foreach (var t in db.measurement_unit)
items.Add(new SelectListItem() { Text = t.name.ToString(), Value =t.id_um.ToString() });
ViewData["UM"] = new SelectList(items, "Value", "Text");
Now, for the view:
<%: Html.DropDownListFor(model=>model.id_um, (IEnumerable <SelectListItem>)ViewData["UM"])%>
But I get the following error:
The ViewData item that has the key 'id_um' is of type 'System.Int32' but must be of type 'IEnumerable<SelectListItem>'.
I struggled with this thing before and I successfully made it work before but I accidentally deleted that project. Please tell me what am I doing wrong? Thanks!
Upvotes: 4
Views: 2850
Reputation: 1039498
I would recommend you using a view model instead of ViewData
. It will make the code much cleaner/safer/refactor friendlier/Intellisense enabled/easier to unit test/magic strings free/....:
public class MyViewModel
{
public int Id { get; set; }
public IEnumerable<SelectListItem> Items { get; set; }
}
Contoller:
public class HomeController: Controller
{
public ActionResult Index()
{
var model = new MyViewModel
{
Items = db.measurement_unit.Select(x => new SelectListItem
{
Value = x.id_um.ToString(),
Text = x.name.ToString()
})
};
return View(model);
}
}
and finally in the strongly typed view:
<%= Html.DropDownListFor(
x => x.Id,
new SelectList(Model.Items, "Value", "Text")
) %>
Upvotes: 5