HSSFWorkbook book = new HSSFWorkbook();

 MemoryStream ms = new MemoryStream();

 ISheet sheet = book.CreateSheet("sheet1");

 ICellStyle cellStyle = book.CreateCellStyle();

 // 首列

 NPOI.SS.UserModel.IRow row1 = sheet.CreateRow();

 row1.CreateCell().SetCellValue(System.DateTime.Now.Year+"年XXXX");

 //设置单元格的样式：水平对齐居中

 row1.Cells[].CellStyle.VerticalAlignment = VerticalAlignment.Justify;//垂直对齐(默认应该为center，如果center无效则用justify)

 row1.Cells[].CellStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;//水平对齐

 CellRangeAddress cellRangeAddress = new CellRangeAddress(, , , );//开始行的索引,结束行的索引,开始列的索引,结束列的索引

 sheet.AddMergedRegion(cellRangeAddress);//要合并单元格所在的sheet

   NPOI.SS.UserModel.IRow row = sheet.CreateRow();

             row.CreateCell().SetCellValue("序号");

             row.CreateCell().SetCellValue("单位");

             row.CreateCell().SetCellValue("姓名");

             row.CreateCell().SetCellValue("性别");

             row.CreateCell().SetCellValue("年龄");

             row.CreateCell().SetCellValue("民族");

             row.CreateCell().SetCellValue("培训班名称");

             row.CreateCell().SetCellValue("电报号");

             row.CreateCell().SetCellValue("培训时间");

             sheet.SetColumnWidth(,  * );//设置列宽

             sheet.SetColumnWidth(, *);

             sheet.SetColumnWidth(,  * );

             sheet.SetColumnWidth(, *);