.NET6 给单元格设置背景色并导出Excel

        /// <summary>
        /// 给单元格设置背景色
        /// </summary>
        /// <returns></returns>
        public async Task<IActionResult> CollectExport()
        {
            #region 表头样式
            IWorkbook book = new HSSFWorkbook();
            ISheet sheet1 = book.CreateSheet("Sheet1");
            IRow row1 = sheet1.CreateRow(0);
            row1.HeightInPoints = 20;
            #endregion

            #region 表头样式及字体
            ICellStyle headStyle = book.CreateCellStyle();
            headStyle.Alignment = HorizontalAlignment.Center;
            IFont font = book.CreateFont();
            font.FontHeightInPoints = 12;
            font.Boldweight = 500;
            headStyle.SetFont(font);
            #endregion

            #region 表体样式及字体
            ICellStyle bodyStyle = book.CreateCellStyle();
            bodyStyle.Alignment = HorizontalAlignment.Center;
            //headStyle.Alignment = CellHorizontalAlignment;
            IFont fontbody = book.CreateFont();
            fontbody.FontHeightInPoints = 10;
            fontbody.Boldweight = 500;
            bodyStyle.SetFont(fontbody);
            #endregion

            #region 添加背景颜色
            ICellStyle cellStyle = book.CreateCellStyle();
            cellStyle.FillPattern = FillPattern.SolidForeground;
            cellStyle.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.LemonChiffon.Index;
            cellStyle.Alignment = HorizontalAlignment.Center;
            #endregion

            #region 把数据给npoi
            DataTable dt = new DataTable();
            if (10 > 0)
            {
                string strs = "序号,客户,项目名称,编号,中标日期,报价人,审核人,中标金额,成本价,备注";
                string[] strArry = strs.Split(',');
                for (int i = 0; i < strArry.Length; i++)
                {
                    row1.CreateCell(i).SetCellValue(strArry[i]);
                    row1.GetCell(i).CellStyle = headStyle;
                }
                for (int i = 0; i < 10; i++)
                {
                    NPOI.SS.UserModel.IRow rowtemp = sheet1.CreateRow(i + 1);
                    rowtemp.HeightInPoints = 15;
                    rowtemp.CreateCell(0).SetCellValue(i + 1); //序号
                    rowtemp.GetCell(0).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(0, 5 * 256);

                    rowtemp.CreateCell(1).SetCellValue("客户"); //客户
                    rowtemp.GetCell(1).CellStyle = cellStyle;
                    sheet1.SetColumnWidth(1, 20 * 256);
                    rowtemp.CreateCell(2).SetCellValue("客户"); //项目名称
                    rowtemp.GetCell(2).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(2, 25 * 256);
                    rowtemp.CreateCell(3).SetCellValue("客户"); //编号
                    rowtemp.GetCell(3).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(3, 25 * 256);
                    rowtemp.CreateCell(4).SetCellValue("客户"); //中标日期
                    if (i % 2 == 0)
                    {
                        rowtemp.GetCell(4).CellStyle = cellStyle;
                    }
                    sheet1.SetColumnWidth(4, 10 * 256);

                    rowtemp.CreateCell(5).SetCellValue("客户"); //报价人
                    rowtemp.GetCell(5).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(5, 10 * 256);
                    rowtemp.CreateCell(6).SetCellValue("客户"); //审核人
                    rowtemp.GetCell(6).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(6, 10 * 256);

                    rowtemp.CreateCell(7).SetCellValue("客户"); //中标金额
                    rowtemp.GetCell(7).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(7, 10 * 256);
                    rowtemp.CreateCell(8).SetCellValue("客户"); //成本价
                    rowtemp.GetCell(8).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(8, 10 * 256);
                    rowtemp.CreateCell(9).SetCellValue("客户"); //备注
                    rowtemp.GetCell(9).CellStyle = bodyStyle;
                    sheet1.SetColumnWidth(9, 25 * 256);
                }
            }
            #endregion

            #region 返回工作流
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            book.Write(ms);
            ms.Seek(0, SeekOrigin.Begin);
            //string FileName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".xls";
            book = null;
            #endregion
            return await Task.FromResult(new FileStreamResult(ms, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
            {
                FileDownloadName = $"{DateTimeOffset.Now:yyyyMMdd_HHmmss}_CollectMaterialPlan.xlsx"
            });
        }