使用NPOI 从网页导出Excel文件(下载自定义Excel文件)

excel文件内容是自定义的，实现了网页导出ex.cel功能

        DataTable dt = new DataTable();

        HSSFWorkbook hssfworkbook;
        using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
        {
            hssfworkbook = new HSSFWorkbook(file);
        }
        HSSFSheet sheet = hssfworkbook.GetSheetAt(0);
        System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

        HSSFRow headerRow = sheet.GetRow(0);
        int cellCount = headerRow.LastCellNum;

        for (int j = 0; j < cellCount; j )
        {
            HSSFCell cell = headerRow.GetCell(j);
            dt.Columns.Add(cell.ToString());
        }