FoodListColumnTemplate class.

FoodListColumnTemplate.cs

public class FoodListColumnTemplate : ITemplate
{
  public void InstantiateIn(Control container)
  {
    var list = new DropDownList();
    list.DataBinding += OnDataBinding;
    container.Controls.Add(list);
  }

  private void OnDataBinding(object sender, EventArgs e)
  {
    var list = (DropDownList) sender;
    var row = (DataGridItem) list.NamingContainer;
    var canine = (ICanine) row.DataItem;
    Action<Food> add = food => { if (canine.Eats(food)) { list.Items.Add(food.ToString()); } };
    add(Food.Biscuit);
    add(Food.Meatballs);
    add(Food.You);
  }
}