private void exportToolStripMenuItem_Click(object sender, EventArgs e)
        {
            var appPath = AppDomain.CurrentDomain.BaseDirectory;
            // creating Excel Application
            Microsoft.Office.Interop.Excel._Application app = new Microsoft.Office.Interop.Excel.Application();
            // creating new WorkBook within Excel application
            Microsoft.Office.Interop.Excel._Workbook workbook = app.Workbooks.Add(Type.Missing);
            // creating new Excelsheet in workbook
            Microsoft.Office.Interop.Excel._Worksheet worksheet = null;
            // see the excel sheet behind the program
            app.Visible = false;
            // get the reference of first sheet. By default its name is Sheet1.
            // store its reference to worksheet
            worksheet = workbook.ActiveSheet;
            // changing the name of active sheet
            worksheet.Name = "Test";
            // storing header part in Excel
            for (int i = 1; i < GRID.Columns.Count + 1; i++)
            {
                worksheet.Cells[1, i] = GRID.Columns[i - 1].HeaderText;
            }
            // storing Each row and column value to excel sheet
            for (int i = 0; i < GRID.Rows.Count - 1; i++)
            {
                for (int j = 0; j < GRID.Columns.Count; j++)
                {
                    worksheet.Cells[i + 2, j + 1] = GRID.Rows[i].Cells[j].Value.ToString();
                }
            }
            // save the application

            workbook.SaveAs(appPath + "test", Microsoft.Office.Interop.Excel.XlFileFormat.xlWorkbookDefault, Type.Missing, Type.Missing,
            false, false, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange,
            Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            app.Quit();

        }

        private void importToolStripMenuItem_Click(object sender, EventArgs e)
        {
            var name = "Test";
            var appPath = AppDomain.CurrentDomain.BaseDirectory;
            var connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" +
                            appPath + "test.xlsx"+
                            ";Extended Properties='Excel 12.0 XML;HDR=YES;';";

            var oDbConnection = new OleDbConnection(connectionString);
            var oDbCommand = new OleDbCommand("Select * From [" + name + "$]", oDbConnection);
            oDbConnection.Open();

            var dataAdapter = new OleDbDataAdapter(oDbCommand);
            var dataTable = new DataTable();
            dataAdapter.Fill(dataTable);
            GRID.DataSource = dataTable.DefaultView;
        }