string xlsfile = "file.xls";
            string sConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + xlsfile + ";Extended Properties=\"Excel 8.0;\"";
            OleDbConnection objConn = new OleDbConnection(sConnectionString);

            try
            {

                objConn.Open();


                OleDbCommand objCmdSelect = new OleDbCommand("SELECT * FROM [FOGLIO_1$]", objConn);
                OleDbDataAdapter objAdapter1 = new OleDbDataAdapter();
                objAdapter1.SelectCommand = objCmdSelect;
                DataSet objDataset1 = new DataSet();
                objAdapter1.Fill(objDataset1);//, "XLData");
                objConn.Close();