ขอสอบถามเกี่ยวกับการ Export หลาย gridviews เป็น Excel เป็นหลายๆ Worksheet ครับ

  SqlDataAdapter da3 = new SqlDataAdapter();
                    SqlCommand cmd3 = new SqlCommand();
                    cmd3.CommandText = "SELECT a.Date_Time,a.Value_Per_15min AS WL FROM TStatus a" + " "
                    + "WHERE a.TagID in ('03020') AND  a.Date_Time >= @p_StartDate AND a.Date_Time < @p_EndDate";
                    cmd3.Parameters.Add("@p_StartDate", SqlDbType.DateTime).Value = dateTimePicker1.Value.Date;
                    cmd3.Parameters.Add("@p_EndDate", SqlDbType.DateTime).Value = dateTimePicker2.Value.Date.AddDays(1);
                    cmd3.Connection = conn;
                    da3.SelectCommand = cmd3;
                    da3.Fill(ds3, "TSEACH3");
                    dv3 = new DataView(ds3.Tables["TSEACH3"]);
                    dataGridView1.DataSource = ds3.Tables["TSEACH3"];


                    SqlDataAdapter da7 = new SqlDataAdapter();
                    SqlCommand cmd7 = new SqlCommand();
                    cmd7.CommandText = "SELECT a.Date_Time,a.Value_Per_15min AS WL FROM TStatus a" + " "
                    + "WHERE a.TagID in ('07020') AND  a.Date_Time >= @p_StartDate AND a.Date_Time < @p_EndDate";
                    cmd7.Parameters.Add("@p_StartDate", SqlDbType.DateTime).Value = dateTimePicker1.Value.Date;
                    cmd7.Parameters.Add("@p_EndDate", SqlDbType.DateTime).Value = dateTimePicker2.Value.Date.AddDays(1);
                    cmd7.Connection = conn;
                    da7.SelectCommand = cmd7;
                    da7.Fill(ds7, "TSEACH7");
                    dv7 = new DataView(ds7.Tables["TSEACH7"]);
                    dataGridView2.DataSource = ds7.Tables["TSEACH7"];

                    Export();
                }
            }
        }

        private void Export()
        {
            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.Name = "ExportedFromDatGrid";
                DataGridView[] gvExcel = new DataGridView[] { dataGridView1, dataGridView2 };
                string[] name = new string[] { "Name1", "Name2"};
                int cellRowIndex = 1;
                int cellColumnIndex = 1;
                for (int ii = 0; ii < gvExcel.Length; ii++)
                {
                    worksheet = workbook.ActiveSheet;
                    worksheet.Name = name[ii].ToString();
                    //Loop through each row and read value from each column. 
                    for (int i = 0; i < gvExcel[ii].Rows.Count - 1; i++)
                    {
                        for (int j = 0; j < gvExcel[ii].Columns.Count; j++)
                        {
                            // Excel index starts from 1,1. As first Row would have the Column headers, adding a condition check. 
                            if (cellRowIndex == 1)
                            {
                                worksheet.Cells[cellRowIndex, cellColumnIndex] = gvExcel[ii].Columns[j].HeaderText;
                            }
                            else
                            {
                                worksheet.Cells[cellRowIndex, cellColumnIndex] = gvExcel[ii].Rows[i].Cells[j].Value.ToString();
                            }
                            cellColumnIndex++;
                        }
                        cellColumnIndex = 1;
                        cellRowIndex++;
                    }
                }

                //Getting the location and file name of the excel to save from user. 
                SaveFileDialog saveDialog = new SaveFileDialog();
                saveDialog.FileName = comboBox1.SelectedItem.ToString() + " วันที่ " + dateTimePicker1.Value.ToString("dd-MMM-yyyy") + " ถึง " + dateTimePicker2.Value.ToString("dd-MMM-yyyy");
                saveDialog.Filter = "Excel Workbooks (*.xlsx)|*.xlsx|Excel 97-2003 Workbooks (*.xls)|*.xls|CSV (Comma delimited)(*.csv)|.csv|All files (*.*)|*.*";
                saveDialog.FilterIndex = 1;

                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;
            }
        }