Cómo vincular datos de LINQ a la lista desplegable

Question

Las dos últimas líneas de este código no funcionan correctamente; los resultados provienen de la consulta LINQ. No estoy seguro de simplemente cómo enlazar con éxito las columnas indicadas en los resultados en el campo de texto y el campo de Valor de la lista desplegable:

protected void BindMarketCodes() 
    { 
     List<lkpMarketCode> mcodesList = new List<lkpMarketCode>(); 

     LINQOmniDataContext db = new LINQOmniDataContext(); 

     var mcodes = from p in db.lkpMarketCodes 
         orderby 0 
         select p; 

     mcodesList = mcodes.ToList<lkpMarketCode>(); 

     //bind to Country COde droplist 
     dd2.DataSource = mcodesList; 
     dd2.DataTextField = mcodesList[0].marketName; 
     dd2.DataValueField = mcodesList[0].marketCodeID.ToString(); 

    } 

Answer 1

Ver código revisado a continuación

protected void BindMarketCodes() 
{  
    using (var dataContext = new LINQOmniDataContext()) { 
     //bind to Country COde droplist 
     dd2.DataSource = from p in dataContext.lkpMarketCodes 
      orderby p.marketName 
      select new {p.marketCodeID, p.marketName}; 
     dd2.DataTextField = "marketName"; 
     dd2.DataValueField = "marketCodeID"; 
     dd2.DataBind(); 
    } 
} 

Answer 2

protected void BindMarketCodes() 
{ 
    using(var dc = new LINQOmniDataContext()) 
    { 
     dd2.DataSource = from p in db.lkpMarketCodes 
         orderby 0 
         select new {p.marketName, p.marketCodeID }; 
     dd2.DataTextField = "marketName"; 
     dd2.DataValueField = "marketCodeID"; 
     dd2.DataBind(); 
    } 
} 

// no need to use ToList() 
// no need to use a temp list; 
// using an anonymous type will limit the columns in your resulting SQL select 
// make sure to wrap in a using block; 

Answer 3

DropDownList ddl_RouteLocation = (DropDownList)e.Row.FindControl("ddl_RouteLocation"); 

ddl_RouteLocation.DataSource = dtLocation;--(dtlocation i have return method of linq in dtlocation) 
ddl_RouteLocation.DataTextField =dtLocation.Rows[0]"LocationName"].ToString(); 
ddl_RouteLocation.DataValueField =dtLocation.Rows[0]["LocationId"].ToString(); 
ddl_RouteLocation.DataBind(); 
ddl_RouteLocation.Items.Insert(0, new ListItem("--Select--", "0"));