linq - MVC3 Razor @Html.DropDownListFor

Question

I could use some help implementing @Html.DropDownListFor. My objective is to filter the list of Products by Category.

This code will display a list box:

@model IEnumerable<Sample.Models.Product>
@{
    List<Sample.Models.Category> list = ViewBag.Categories;
    var items = new SelectList(list, "CategoryID", "CategoryName");

}
@Html.DropDownList("CategoryID", items)

But I'm having trouble getting @Html.DropDownListFor to work:

@model IEnumerable<Sample.Models.Product>
@{
    List<Sample.Models.Category> list = ViewBag.Categories;
    var items = new SelectList(list, "CategoryID", "CategoryName");

}
@Html.DropDownListFor(???, @items)

I could use some help constructing the Linq portion of @Html.DropDownListFor. Here is the model:

public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
    public int CategoryID { get; set; }
    public string QuantityPerUnit { get; set; }
    public Decimal? UnitPrice { get; set; }
    public short UnitsInStock { get; set; }

    public virtual Category Category { get; set; }
}

public class Category
{
    public int CategoryID { get; set; }
    public string CategoryName { get; set; }

    public virtual ICollection<Product> Products { get; set; }

}

Answer 1

Your view is strongly typed to a collection of products so I suppose that you need a drop down for each product. If this is the case an editor template would work:

@model IEnumerable<Sample.Models.Product>
@Html.EditorForModel()

And then inside ~/Views/Shared/EditorTemplates/Product.cshtml

@model Sample.Models.Product
@{
    List<Sample.Models.Category> list = ViewBag.Categories;
    var items = new SelectList(list, "CategoryID", "CategoryName");
}
@Html.DropDownListFor(x => x.CategoryID, @items)