How can a multi-select-list be edited using asp.net mvc?

Question

I'd like to edit an object like the one below. I'd like the UsersSelectedList populated with one or more Users from the UsersGrossList.

Using the standard edit-views in mvc, I get only strings and booleans (not shown below) mapped. Many of the examples I find on google utilizes early releases of the mvc framework whereas I use the official 1.0 release.

Any examples of the view is appreciated.

public class NewResultsState
{
    public IList<User> UsersGrossList { get; set; }
    public IList<User> UsersSelectedList { get; set; }
}

Answer 1

Assuming that User model has Id and Name properties:

<%= Html.ListBox("users", Model.UsersGrossList.Select(
    x => new SelectListItem {
        Text = x.Name,
        Value = x.Id,
        Selected = Model.UsersSelectedList.Any(y => y.Id == x.Id)
    }
) %>

Or with View Model

public class ViewModel {
    public Model YourModel;
    public IEnumerable<SelectListItem> Users;
}

Controller:

var usersGrossList = ...
var model = ...

var viewModel = new ViewModel {
    YourModel = model;
    Users = usersGrossList.Select(
        x => new SelectListItem {
            Text = x.Name,
            Value = x.Id,
            Selected = model.UsersSelectedList.Any(y => y.Id == x.Id)
        }
    }

View:

<%= Html.ListBox("users", Model.Users ) %>