How to create a dropDown list in MVC4

Question

Could you help me create a dropdown list in asp.net mvc 4?

I Have a ProjetoFuncionario class that is an associative class of \"Projeto\" and \"Funcionario\"

Answer 1

A drop down list is used for selecting a value from a list of possible options. Its not clear from you model, but assuming you want a view with drop downs to select a Projeto and a Funcionario, then create a view model to represent what you want to display and edit (What is a view model). Note this example is based on the model definitions from your previous question.

public class ProjetoFuncionarioVM
{
  [Display(Name="Projeto")]
  public long SelectedProjeto { get; set; }
  [Display(Name="Funcionario")]
  public long SelectedFuncionario { get; set; }
  public SelectList ProjetoList { get; set; }
  public SelectList FuncionarioList { get; set; }
}

Controller

public ActionResult Edit()
{
  ProjetoFuncionarioVM model = new ProjetoFuncionarioVM();
  model.SelectedProjeto = // if you want to preselect one of the options
  ConfigureEditModel(model);
  return View(model);    
}

public ActionResult Edit(ProjetoFuncionarioVM model)
{
  if (ModelState.IsValid)
  {
    ConfigureEditModel(model); // reassign the select lists
    return View(model); // return the view to correct errors
  }
  // access properties of the view model, save and redirect
}

private void ConfigureEditModel(ProjetoFuncionarioVM model)
{
  List<Projeto> projeto = // get the collection of projeto objects from the database
  List<Funcionario> funcionario = // ditto for funcionario objects
  // Assign select lists
  model.ProjetoList = new SelectList(projeto, "id_Projeto", "nome_Projeto");
  model.FuncionarioList = new SelectList(funcionario, "id_funcionario", "nom_funcionario");
}

View

@model ProjetoFuncionarioVM

@using (Html.BeginForm())
{
  @Html.LabelFor(m => m.SelectedProjeto)
  @Html.DropDownListForFor(m => m.SelectedProjeto, Model.ProjetoList, "Please select")
  @Html.ValidationMessageFor(m => m.SelectedProjeto)
  @Html.LabelFor(m => m.SelectedFuncionario)
  @Html.DropDownListForFor(m => m.SelectedFuncionario, Model.FuncionarioList, "Please select")
  @Html.ValidationMessageFor(m => m.SelectedFuncionario)
  <input type="submit" value="Save" />
}

Refer also SelectList and DropDownListFor for various overloads of these methods

Answer 2

Check out this link. I would suggest adding a property to your view model for the dropdown list and just make sure you populate it before passing it to your view.