public static class HSheetExt

{

        /// <summary>

        /// 将xls中的sheet转为xlsx格式的sheet（保留处理单元格格式以及字体格式）

        /// </summary>

        /// <param name="hSSFSheet"></param>

        /// <param name="dWb"></param>

        /// <returns></returns>

        public static XSSFSheet ConvertToXSheet(this HSSFSheet hSSFSheet, XSSFWorkbook dWb)

        {

            XSSFSheet xSSFSheet = dWb.CreateSheet() as XSSFSheet;

            var rowCount = hSSFSheet.LastRowNum;//行数

            #region 预定义样式和字体信息

            List<XSSFCellStyle> xSSFCellStyles = new List<XSSFCellStyle>();

            List<XSSFFont> xSSFFonts = new List<XSSFFont>();   

            #endregion

            //列宽度处理

            int maxColumnWidth = 256 * 255;

            var xCommnetsDic = ConvertHCommentToXComment(xSSFSheet, hSSFSheet, xSSFFonts);

            for (var i = 0; i <= rowCount; i++)

            {

                var hRow = hSSFSheet.GetRow(i);

                if (hRow == null)

                {

                    continue;

                }

                var xRow = xSSFSheet.CreateRow(i);

                xRow.Height = hRow.Height;

                var curHRowColumnCount = hRow.LastCellNum;//列数

                for(var j = 0;j <= curHRowColumnCount; j++)

                {

                    var orgWidth = hSSFSheet.GetColumnWidth(i);

                    if (orgWidth > maxColumnWidth)

                    {

                        xSSFSheet.SetColumnWidth(i, maxColumnWidth);

                    }

                    else

                    {

                        xSSFSheet.SetColumnWidth(i, orgWidth);

                    }

                    XSSFCell xCell = xRow.CreateCell(j) as XSSFCell;

                    HSSFCell hCell = hRow.GetCell(j) as HSSFCell;

                    ConvertHCellToXCell(hCell, xCell, xSSFCellStyles, xSSFFonts, xCommnetsDic, true);

                }

            }

            //最后处理合并单元格的相关情况

            int sheetMergerCount = hSSFSheet.NumMergedRegions;

            for (int k = 0; k < sheetMergerCount; k++)

                xSSFSheet.AddMergedRegion(hSSFSheet.GetMergedRegion(k));

            return xSSFSheet;

        }

}

   }

}