MVC 進階ListBox和DropDownList

首先要到Model.cs記得using System.Web.Mvc;

public List<SelectListItem> see()
        {
            string a = System.Web.Configuration.WebConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;
            SqlConnection conn =new SqlConnection(a);
            conn.Open();
            string sql = "spii";
            SqlCommand cmd = new SqlCommand(sql,conn);
            
            SqlDataReader dr = cmd.ExecuteReader();
            List<SelectListItem> yui = new List<SelectListItem>();
            
            
                for (int i = 0; i <=dr.FieldCount+1; i++)
                {
                    dr.Read();
                    yui.Add(new SelectListItem()
                    {
                        Text = dr[1].ToString(),
                        Value = dr[0].ToString(),
                        Selected = dr[0].Equals(3)
                    });
                }
            
            
            dr.Close();
            cmd.Dispose();
            conn.Close();
            conn.Dispose();
            return yui;
            
        }

接著利用List將資料return
回到Controll那邊:

Model ty = new Model();
public ActionResult Index()
{
    ViewBag.select1 = ty.see();
    ViewBag.select2 = ty.see();
}

再回到View:
@Html.ListBox("select1", null, new { id="SelectList2",size="2"})
@Html.DropDownList("select2",null ,new { id="Select2"})
大功告成!!