C# 엑셀 파일 열고 닫기

            Application AppExcel = null;
            Workbook workBook = null;
            Worksheet workSheet = null;

            try
            {
                AppExcel = new Application
                {
                    Visible = true
                };

                workBook = AppExcel.Workbooks.Add();
                workSheet = workBook.Worksheets.Add(Before: workBook.Worksheets.Item[1]);
				
                // 여기에 코드를 작성하시오
                

                workBook.SaveAs(@"d:\"+ DateTime.Now.ToString("HHmmss")+".xlsx", XlFileFormat.xlWorkbookDefault);
            }
            catch (Exception e)
            {
               
            }
            finally
            {
                workBook.Close();
                AppExcel.Quit();

                Marshal.ReleaseComObject(workSheet);
                Marshal.ReleaseComObject(workBook);
                Marshal.ReleaseComObject(AppExcel);
            }