EXCEL

public DataTable ExcelToDataTable(string strExcelFileName, string strSheetName)
        {
            string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + strExcelFileName + ";" + "Extended Properties=Excel 5.0;";
            string strExcel = string.Format("select * from [{0}$]", strSheetName);
            DataSet ds = new DataSet();
            using (OleDbConnection conn = new OleDbConnection(strConn))
            {
                conn.Open();
                OleDbDataAdapter adapter = new OleDbDataAdapter(strExcel, strConn);
                adapter.Fill(ds, strSheetName);
                conn.Close();
            }
            return ds.Tables[strSheetName];
        }