Group By in Linq

// Group by With Linq

   List<string> ls = new List<string>();

   using (LinqModel.LinqEntities ST1 = new LinqModel.LinqEntities())

   {

       var V = (from State in ST1.State_Master

                    group State by State.CountryID into temp

                    select new

                         {

                             T1 = temp.Key.Value,

                             T2 = temp

                         }).ToList();

               

                foreach (var c in V)

                {

                    for (int i = 0; i < c.T2.ToList().Count; i++)

                    {

                        ls.Add(c.T2.ToList()[i].StateName);

                    }

                }

   };

   // Group by With Linq using Lambada expression

   // Same Result as above

  

   using (LinqModel.LinqEntities ST1 = new LinqModel.LinqEntities())

   {

    var vLambada = ST.State_Master.GroupBy(state => state.CountryID).ToList();

  

          foreach (var state in vLambada)

            {

                for (int i = 0; i < state.Count(); i++)

                {

                    ls.Add(state.ToList()[i].StateName);

                }

            }

    };

            Rpt.DataSource = ls;

            Rpt.DataBind();