Exporter des données à un fichier excel

        private void btnExporter_Click(object sender, EventArgs e)
        {
            // Creating a Excel object. 
            Microsoft.Office.Interop.Excel._Application excel = new Microsoft.Office.Interop.Excel.Application();
            Microsoft.Office.Interop.Excel._Workbook workbook = excel.Workbooks.Add(Type.Missing);
            Microsoft.Office.Interop.Excel._Worksheet worksheet = null;

            try
            {
                worksheet = workbook.ActiveSheet;
                worksheet.Name = "ExportedFromDatGrid";

                int cellRowIndex = 1;
                int cellColumnIndex = 2;
                int b = 50;
                int c = 100;
                int d = 150;
                String Date = System.DateTime.Now.ToShortDateString();
                int minute = System.DateTime.Now.Minute; // les minutes 
                int heure = System.DateTime.Now.Hour; // l'heure 

                string HEURE = heure.ToString() + ":" + minute.ToString();
                string DATE = Date + " " + HEURE;
                MessageBox.Show("DATE = " + DATE);

                worksheet.Cells[1, 1] = ":DATE";
                worksheet.Cells[2, 1] = ":GROUP No.";
                worksheet.Cells[3, 1] = ":GROUP NAME";
                worksheet.Cells[4, 1] = "ITEM NAME";
                worksheet.Cells[1, 2] = DATE;
                worksheet.Cells[2, 2] = "1";
                worksheet.Cells[3, 2] = "essai";
                worksheet.Cells[4, 2] = "VALUE";
                 
                cellRowIndex = 5;
                
                #region variateur1
                    if (Variateur1.index != 0)
                    {                      
                        cellColumnIndex = 2;
                        for (int i = 1; i <= 50; i++)
                        {
                            if (Variateur1.tab_seq[99 + i] == 0)
                            {
                                worksheet.Cells[cellRowIndex, cellColumnIndex] = 0;
                            }
                            else
                            {
                                worksheet.Cells[cellRowIndex, cellColumnIndex] = i;
                            }
                            cellRowIndex = cellRowIndex + 1;
                        }
                        for (int i = 0; i <= 49; i++)
                        {
                            worksheet.Cells[cellRowIndex, cellColumnIndex] = Variateur1.tab_seq[b + i];
                            cellRowIndex = cellRowIndex + 1;
                        }
                        for (int i = 0; i <= 49; i++)
                        {
                            worksheet.Cells[cellRowIndex, cellColumnIndex] = Variateur1.tab_seq[c + i];
                            cellRowIndex = cellRowIndex + 1;
                        }
                        for (int i = 0; i <= 49; i++)
                        {
                            if (i == 49)
                            {
                                worksheet.Cells[cellRowIndex, cellColumnIndex] = Variateur1.NbMaille;
                            }
                            else
                            {
                                if (option.mmrack1 == 1)
                                {
                                    worksheet.Cells[cellRowIndex, cellColumnIndex] = Variateur1.tab_seq[d + i];
                                }
                                else if (option.maillecm1 == 1)
                                {
                                    worksheet.Cells[cellRowIndex, cellColumnIndex] = Variateur1.tabf_seq[d + i] * 100;
                                }
                            }
                            cellRowIndex = cellRowIndex + 1;
                        }
                    }                      
                #endregion

                //Getting the location and file name of the excel to save from user. 
                SaveFileDialog saveDialog = new SaveFileDialog();
                saveDialog.Filter = "CSV files (*.csv)|*.csv|All files (*.*)|*.*";
                saveDialog.FilterIndex = 2;

                if (saveDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
                {
                    workbook.SaveAs(saveDialog.FileName);
                    MessageBox.Show("Export Successful");
                }
            }
            catch (System.Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                excel.Quit();
                workbook = null;
                excel = null;
            }