C# Generate Excel Sample SQL Database Export Excel

using System;
using ;
using ;
using ;
using ;
using ;

namespace ListToExcel
{
    class Program
    {
        static List<objtype> objs = new List<objtype>();
        static void Main(string[] args)
        {
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            (new objtype() { name = "allen", val = "aaa" });
            ExportDataToExcel("", "", @"c:\", "a");
        }
        /// <summary>
//// Export data directly to excel
        /// </summary>
/// <param name="connectionString">Connection String</param>
/// <param name="sql">Query statement</param>
/// <param name="fileName">File name</param>
/// <param name="sheetName">Table name</param>
        static void ExportDataToExcel(string connectionString, string sql, string fileName, string sheetName)
        {
            Application app = new Application();
            Workbook wb = ();
            Worksheet ws = (, , , ) as Worksheet;
             = sheetName;
            try
            {
                int n = 0;

                for (int i = 1; i < ; i++)
                {
                      var excelRange = (Range)[i, 1];
                   excelRange.Value2 = objs[i].val;//Value2?
                   excelRange = null;
                }
            }
            catch (Exception ex)
            {
                string str = ;
            }
            finally
            {
                 = true;
(fileName);//Save
();//Close the process
            }
        }
    }
    class objtype
    {
        public string name { get; set; }
        public string val { get; set; }
    }
}