Like I create a Dropdownlist for MVC5 ASP.NET

Question

Hello I’m having difficulty making a Dropdownlist, I have 3 classes a Entities to have relationship with the bank, A Gender that is associated with the Work class.

[Table("Generos")]
public class Genero
{
    [Key]
    public int GeneroId { get; set; }

    public string NomeGenero { get; set; }

    public string Descricao { get; set; }

    public List<Obra> Obras { get; set; }
}

[Table("Obras")]
public class Obra
{
    [Key]
    public int ObraId { get; set; }

    public string NomeObra { get; set; }

    public string Autor { get; set; }

    public string Editora { get; set; }

    public string DescricaoObra { get; set; }

    public int GeneroId { get; set; }
}

I’m not getting the Dropdownlist, there’s some way to do it?

Answer 1

Come on...

As there is very little information in the question, I will assume some things, in order to set an example that may be useful to you.

I’ll give you a hint of how you can create your DropDownList there are other ways to create, but I’ll suggest it the way I do it.

I will assume that a Genero has several works, then his models will stay like this:

[Table("Generos")]
public class Genero
{
    [Key]
    public int GeneroId { get; set; }

    public string NomeGenero { get; set; }

    public string Descricao { get; set; }

    public virtual ICollection<Obra> Obras { get; set; }
}

[Table("Obras")]
public class Obra
{
    [Key]
    public int ObraId { get; set; }
    public int GeneroId { get; set; }

    public string NomeObra { get; set; }

    public string Autor { get; set; }

    public string Editora { get; set; }

    public string DescricaoObra { get; set; }

    public virtual Genero Genero { get; set; }
}

So, your Create Obrascontroller will look like this:

  public ActionResult Create()
  {
      //Aqui preenche-se uma ViewBag para usar na View
      ViewBag.Generos = db.Generos.ToList();
      return View();
  }

And its View de Create will look like this:

 <div class="col-md-3">
    <label class="control-label">Status</label>
    @Html.DropDownListFor(model => model.ObraId, ((IEnumerable<Genero>)ViewBag.Generos).Select(option => new SelectListItem
    {
       Text = option.NomeGenero,
       Value = option.GeneroId.ToString(),
       Selected = (Model != null) && (Model.ObraId == option.GeneroId)
    }), "Selecione um Gênero...", new { @class = "form-control", @placeholder = "Genero" })
 </div>

Doing so, in creating a work you will be able to choose which genre it belongs to.