Create a DropDown List from a db Entity MVC5 - asp.net-mvc-5

Question

I want to create a dropdown list based on the contents of a db entity.
This seems like a simple enough concept but I can't really seem to pin it down.
Here's my code:
MODEL
public partial class Escuela
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public Escuela()
{
this.Empleadoes = new HashSet<Empleado>();
}
public int ID { get; set; }
public string Nombre { get; set; }
public int PuestoID { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Empleado> Empleadoes { get; set; }
public virtual Puesto Puesto { get; set; }
}
public partial class ESCUELAEntities : DbContext
{
public ESCUELAEntities()
: base("name=ESCUELAEntities")
{
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
throw new UnintentionalCodeFirstException();
}
public virtual DbSet<Alumno> Alumnoes { get; set; }
public virtual DbSet<Empleado> Empleadoes { get; set; }
public virtual DbSet<Escuela> Escuelas { get; set; }
public virtual DbSet<Grupo> Grupoes { get; set; }
public virtual DbSet<Puesto> Puestoes { get; set; }
}
CONTROLLER
public ActionResult Index()
{
// HAVE TRIED THESE THREE
// #1
var EscQry = from d in db.Escuelas
select d.Nombre;
var escuelas = new SelectList(EscQry, "ID", "Nombre");
ViewData["esc"] = escuelas;
// #2
var escuelas = new SelectList(from d in db.Escuelas
select new SelectListItem { Text = d.Nombre, Value = d.ID.ToString() });
ViewData["esc"] = escuelas;
// #3
IEnumerable<Escuela> model = from p in db.Escuelas
select new Escuela { Nombre = p.Nombre };
// #1
return View();
// #2
return View();
// #3
return View(model);
}
VIEW
#model IEnumerable<_3E_III.Models.Escuela>
#{
ViewBag.Title = "Home Page";
}
#Html.DropDownList("Escuelas", ViewData["esc"] as List<SelectListItem>)
I get this error.
There is no ViewData item of type 'IEnumerable' that has the key 'Escuelas'.

Answer 1

I would make a View Model of the domain class, based on what properties I would need to show in my view.
public class EscuelaViewModel
{
public int ID { get; set; }
public string Nombre { get; set; }
public int PuestoID { get; set; }
.............. etc.
public Collection<SelectListItem> Escuelas {get; set;}
private static Collection<SelectListItem> CreateEscuelasOptions(string selectedOption == "")
{
var model = from p in db.Escuelas select new Escuela { Number = p.Nombre, Id= p.Id };
var options = new Collection<SelectListItem>();
foreach(var esc in model)
options.Add(new SelectListItem {Value = esc.Id, Text = esc.Number, Selected = selectedOption.Equals(esc.Number)});
return options;
}
public void LoadViewData()
{
Escuelas = CreateEscuelasOptions(Nombre);
}
}
Then, in the Controller:
public ActionResult Index()
{
var EscuelaViewModel = new EscuelaViewModel();
EscuelaViewModel.LoadViewData();
return View(EscuelaViewModel);
}
And the View:
#model EscuelaViewModel
#{
ViewBag.Title = "Home Page";
}
#Html.DropDownListFor(x => x.Nombre, Model.Escuelas, --Select option--)