C#

var rows = GetDataGridRows(dataGrid);

            List<string> s = new List<string>();
            foreach (DataGridRow row in rows)
            {
                
                var column = dataGrid.Columns[0];

                var tb = column.GetCellContent(row);
                var r = (DataRowView)tb.DataContext;

                Object[] obj = r.Row.ItemArray;

                s.Add(obj[0].ToString());


                 ids = string.Join(",", s);               
            }
            MessageBox.Show(ids);

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Threading.Tasks;



namespace Scenario1
{
    public partial class companies1 : System.Web.UI.Page
    {
        public static ArrayList Files = new ArrayList();
        protected void Page_Load(object sender, EventArgs e)
        {
            string str = "Data Source=BIG-BAD-WOLF-CO\\SQLEXPRESS;Integrated Security=True;Connect Timeout=15;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False";

            SqlConnection con = new SqlConnection(str);
            string com = "select Name from Companies";
            SqlDataAdapter adpt = new SqlDataAdapter(com, con);
            DataSet myDataSet = new DataSet();
            adpt.Fill(myDataSet, "Companies");
            DataTable myDataTable = myDataSet.Tables[0];
            
            DataRow tempRow = null;

            foreach (DataRow tempRow_Variable in myDataTable.Rows)
            {
                tempRow = tempRow_Variable;
                
                listBoxOrg.Items.Add((tempRow["Name"]));
            }

        }
     }
}