using System;

using System.Data;
using System.Data.OleDb;
using System.Collections.Generic;
using System.Text;


namespace Excelcalling1
{
    class Program
    {
        static void Main(string[] args)
        {
            string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;
                    Data Source=E:\SheetForTest.xls;Integrated Security=SSPI;
                    Extended Properties=Microsoft Excel 11.0 Object Library";

            //Create the connection

            System.Data.OleDb.OleDbConnection ExcelConnection =
            new System.Data.OleDb.OleDbConnection
                             (ConnectionString);

            //create a string for the query

            string ExcelQuery;

            //Sheet1 is the sheet name
            //create the query:
            //read column with heading A from the Excel file

            ExcelQuery = "Select A from [Sheet1$]"; // from Sheet1";

            //use "Select * ... " to select the entire sheet
            //create the command

            System.Data.OleDb.OleDbCommand ExcelCommand = new System.Data.OleDb.OleDbCommand(ExcelQuery, ExcelConnection);

            //Open the connection

            //ExcelConnection.Open();
            try
            {
                ExcelConnection.Open();
            }
            catch (OleDbException e)
            {
                string errorMessages = "";

                for (int i = 0; i < e.Errors.Count; i++)
                {
                    errorMessages += "Index #" + i + "\n" +
                                     "Message: " + e.Errors[i].Message + "\n" +
                                     "NativeError: " + e.Errors[i].NativeError + "\n" +
                                     "Source: " + e.Errors[i].Source + "\n" +
                                     "SQLState: " + e.Errors[i].SQLState + "\n";
                }

                System.Diagnostics.EventLog log = new System.Diagnostics.EventLog();
                log.Source = "My Application";
                log.WriteEntry(errorMessages);
                Console.WriteLine("An exception occurred. Please contact your system administrator.");
            }

            //Create a reader

            System.Data.OleDb.OleDbDataReader ExcelReader;
            ExcelReader = ExcelCommand.ExecuteReader();

            //For each row after the first
            //Message box the values in the first column i.e. column 0

            while (ExcelReader.Read())
            {
                //MessageBox.Show((ExcelReader.GetValue(0)).ToString());
                Console.WriteLine("value retrieved!!");
            }
            ExcelConnection.Close();

            
        }
    }
}

using System;

using System.Data;
using System.Data.OleDb;
using System.Collections.Generic;
using System.Text;

//using Microsoft Office Excel 2003 11.0;
//using Excel;

namespace Excelcalling1
{
    class Program
    {
        static void Main(string[] args)
        {

                        string F1Name = "E:\\SheetForTest.xls";

                        string CnStr = ("Provider=Microsoft.Jet.OLEDB.4.0;" + ("Data Source="

                        + ( F1Name + (";" + "Extended Properties=\"Excel 8.0;\""))));

                        DataTable DT = new DataTable();

                        OleDbDataAdapter DA = new OleDbDataAdapter("Select * from [Sheet1$]", CnStr);

                        Console.WriteLine("File Accessed!!!!");

                try

                {  

                    DA.Fill(DT);

                    //dataGridView1.DataSource = DT;

                }

                catch (Exception ex)

                {

                    Console.WriteLine(ex.Message);

                }

              

        }
    }
}