Excel 내보내기

     Excel.Application xapp = new Excel.Application();
                xapp.Application.Workbooks.Add(true);
                Excel.Worksheet xsheet = xapp.Sheets[1];
                xsheet.Cells[1,1] = " ";
               string filepath =@"D:\XX.xls";//  ;
                xsheet.SaveAs(filepath);
                        
                xapp.Workbooks.Close();
                xapp.Quit();
                System.GC.Collect();

 public void RenderDataTableToExcel(DataTable SourceTable)
        {
            // 
            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet();
            HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
            // 
            foreach (DataColumn column in SourceTable.Columns)
            {
                headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
            }
            // 
            int rowIndex = 1;
            foreach (DataRow row in SourceTable.Rows)
            {
                HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
                foreach (DataColumn column in SourceTable.Columns)
                {
                    dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
                }
                rowIndex++;
            }
            // 
            string path = Server.MapPath("~/UpFiles/ReportResult/") + "test.xls";
            FileStream file = new FileStream(path, FileMode.Create);
            workbook.Write(file);
            // ， 
            file.Close();
            sheet = null;
            headerRow = null;
            workbook = null;
        }