public void Output(DataTable table, string SheetName, string reportName)

        {

            string result = string.Empty;

            try

            {

                HSSFWorkbook workBook = new HSSFWorkbook();

                ISheet sheet = workBook.CreateSheet(SheetName);  //sheet页名称

                NPOI.SS.UserModel.IFont font = workBook.CreateFont();

                font.FontName = "微软雅黑";

                font.FontHeight = 175;

                ICellStyle style = workBook.CreateCellStyle();

                style.Alignment = HorizontalAlignment.Center;

                style.VerticalAlignment = VerticalAlignment.Center;

                style.SetFont(font);

                style.WrapText = true;

                IRow rows = sheet.CreateRow(0);

                rows.Height = 400;

                rows.CreateCell(0).SetCellValue(reportName);   //报表名称

                rows.GetCell(0).CellStyle = style;

                sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, table.Columns.Count - 1));

                rows = sheet.CreateRow(1);

                for (int i = 0; i < table.Columns.Count; i++)

                {

                    rows.CreateCell(i).SetCellValue(table.Columns[i].ColumnName.ToString());

                    rows.Sheet.SetColumnWidth(i, 4000);

                    rows.GetCell(i).CellStyle = style;

                }

                ICellStyle style2 = workBook.CreateCellStyle();

                style2.Alignment = HorizontalAlignment.Left;

                style2.VerticalAlignment = VerticalAlignment.Center;

                style2.SetFont(font);

                style2.DataFormat = HSSFDataFormat.GetBuiltinFormat("@");

                //style2.WrapText = true;

                int tem = 0;

                int sheetCount = 1;

                for (int j = 1; j <= table.Rows.Count; j++)

                {

                    tem++;

                    if (tem == 60000)//每页最多导出60000

                    {

                        tem =0;

                        sheetCount++;

                        sheet = workBook.CreateSheet(SheetName + sheetCount);

                        rows = sheet.CreateRow(0);

                        for (int i = 0; i < table.Columns.Count; i++)

                        {

                            rows.CreateCell(i).SetCellValue(table.Columns[i].ColumnName.ToString());

                            rows.Sheet.SetColumnWidth(i, 4000);

                            rows.GetCell(i).CellStyle = style;

                        }

                    }

                    IRow row = sheet.CreateRow(tem + 1);

                    for (int k = 0; k < table.Columns.Count; k++)

                    {

                        row.CreateCell(k).SetCellValue(table.Rows[j - 1][k].ToString());

                        row.Sheet.SetColumnWidth(k, 4000);

                        row.GetCell(k).CellStyle = style2;

                    }

                    #region

                    //Row row = sheet.CreateRow(j + 1);

                    //for (int k = 0; k < table.Columns.Count; k++)

                    //{

                    //    row.CreateCell(k).SetCellValue(table.Rows[j - 1][k].ToString());

                    //    row.GetCell(k).CellStyle = style2;

                    //}

                    #endregion

                }

                int maxColumn = table.Columns.Count;

                //列宽自适应，只对英文和数字有效

                //for (int i = 0; i <= maxColumn; i++)

                //{

                //    sheet.AutoSizeColumn(i);

                //}

                using (MemoryStream ms = new MemoryStream())

                {

                    workBook.Write(ms);

                    ms.Flush();

                    ms.Position = 0;

                    workBook = null;

                    HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";//HttpContext.Current.Response

                    string browser = HttpContext.Current.Request.Browser.Browser.ToString();

                    string header = string.Empty;

                    if (browser == "Firefox")

                    {

                        header = string.Format("attachment; filename={0}", string.Format("{0}-{1}.xls", reportName, DateTime.Now.ToString("yyyy-MM-dd")), Encoding.UTF8).ToString();

                    }

                    else

                    {

                        header = string.Format("attachment; filename={0}", HttpUtility.UrlEncode(string.Format("{0}-{1}.xls", reportName, DateTime.Now.ToString("yyyy-MM-dd")), Encoding.UTF8)).ToString();

                    }

                    HttpContext.Current.Response.AddHeader("Content-Disposition", header);

                    HttpContext.Current.Response.Clear();

                    HttpContext.Current.Response.BinaryWrite(ms.GetBuffer());

                    HttpContext.Current.Response.End();

                }

            }

            catch

            {

                throw new Exception("导出异常");

            }

        }