NOPI对Excel的2003和2007的支持

这段时间在做NPOI 发现以前的帮助类只对2003表格支持比较，可是对2007就会报错

没有办法就只能修改帮助类文件了

思路 ：就是把以前写死的转换  现在都变成接口接收 就完美解决掉了对2007的支持 

废话不多说直接上代码：

  /// <summary>
    /// NPOI Excel操作类
    /// </summary>
    public class NPOIExcelHelper
    {
        /// <summary>
        /// DataTable导出到Excel文件
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <param name="strFileName">保存位置</param>
        public static void Export(DataTable dtSource, string strHeaderText, string strFileName)
        {
            using (MemoryStream ms = Export(dtSource, strHeaderText))
            {
                using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                {
                    byte[] data = ms.ToArray();
                    fs.Write(data, 0, data.Length);
                    fs.Flush();
                }
            }
        }

        /// <summary>
        /// DataTable导出到Excel的MemoryStream
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        private static MemoryStream Export(DataTable dtSource, string strHeaderText)
        {
            int sheetNum = 1;
            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet("Sheet" + sheetNum);

            #region 右击文件 属性信息
            {
                DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                dsi.Company = "NPOI";
                workbook.DocumentSummaryInformation = dsi;

                string fnINfo = "作者";
                SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                si.Author = fnINfo;         //填加xls文件作者信息
                si.ApplicationName = "";    //填加xls文件创建程序信息
                si.LastAuthor = fnINfo;     //填加xls文件最后保存者信息
                si.Comments = fnINfo;       //填加xls文件作者信息
                si.Title = strHeaderText;   //填加xls文件标题信息
                si.Subject = strHeaderText; //填加文件主题信息
                si.CreateDateTime = DateTime.Now;
                workbook.SummaryInformation = si;
            }
            #endregion

            HSSFCellStyle dateStyle = (HSSFCellStyle)workbook.CreateCellStyle();
            HSSFDataFormat format = (HSSFDataFormat)workbook.CreateDataFormat();
            dateStyle.DataFormat = format.GetFormat("yyyy-MM-dd HH:mm:ss");

            //取得列宽
            int[] arrColWidth = new int[dtSource.Columns.Count];
            foreach (DataColumn item in dtSource.Columns)
            {
                arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
            }
            for (int i = 0; i < dtSource.Rows.Count; i++)
            {
                for (int j = 0; j < dtSource.Columns.Count; j++)
                {
                    int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
                    if (intTemp > arrColWidth[j])
                    {
                        arrColWidth[j] = intTemp;
                    }
                }
            }
            int rowIndex = 0;
            int maxColLen = 32767;//单元格内容（文本）的最大长度数32767 个字符。 
            foreach (DataRow row in dtSource.Rows)
            {
                #region 新建表，填充表头，填充列头，样式
                if (rowIndex == 65535 || rowIndex == 0)
                {
                    if (rowIndex != 0)
                    {
                        sheetNum++;
                        sheet = (HSSFSheet)workbook.CreateSheet("Sheet" + sheetNum);
                    }

                    #region 表头及样式
                    {
                        HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
                        headerRow.HeightInPoints = 20;
                        headerRow.CreateCell(0).SetCellValue(strHeaderText);

                        HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
                        headStyle.Alignment = HorizontalAlignment.Center;
                        HSSFFont font = (HSSFFont)workbook.CreateFont();
                        font.FontHeightInPoints = 16;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);
                        headerRow.GetCell(0).CellStyle = headStyle;
                        sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, dtSource.Columns.Count - 1));
                    }
                    #endregion

                    #region 列头及样式
                    {
                        HSSFRow headerRow = (HSSFRow)sheet.CreateRow(1);
                        HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
                        headStyle.Alignment = HorizontalAlignment.Center;
                        HSSFFont font = (HSSFFont)workbook.CreateFont();
                        font.FontHeightInPoints = 10;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);

                        foreach (DataColumn column in dtSource.Columns)
                        {
                            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                            headerRow.GetCell(column.Ordinal).CellStyle = headStyle;

                            //设置列宽,判断单元格内容（文本）的长度数是否大于32767 个字符。 
                            if ((arrColWidth[column.Ordinal] + 1) * 256 > maxColLen)
                            {
                                sheet.SetColumnWidth(column.Ordinal, maxColLen);
                            }
                            else
                            {
                                sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);
                            }
                        }
                    }
                    #endregion

                    rowIndex = 2;
                }
                #endregion

                #region 填充内容
                HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
                foreach (DataColumn column in dtSource.Columns)
                {
                    HSSFCell newCell = (HSSFCell)dataRow.CreateCell(column.Ordinal);
                    string drValue = row[column].ToString();

                    switch (column.DataType.ToString())
                    {
                        case "System.String"://字符串类型 
                            newCell.SetCellValue((drValue.Length > maxColLen) ? drValue.Substring(0, maxColLen) : drValue);
                            break;
                        case "System.DateTime"://日期类型
                            DateTime dateV;
                            DateTime.TryParse(drValue, out dateV);
                            newCell.SetCellValue(dateV);
                            newCell.CellStyle = dateStyle;//格式化显示
                            break;
                        case "System.Boolean"://布尔型
                            bool boolV = false;
                            bool.TryParse(drValue, out boolV);
                            newCell.SetCellValue(boolV);
                            break;
                        case "System.Int16"://整型
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            int intV = 0;
                            int.TryParse(drValue, out intV);
                            newCell.SetCellValue(intV);
                            break;
                        case "System.Decimal"://浮点型
                        case "System.Double":
                            double doubV = 0;
                            double.TryParse(drValue, out doubV);
                            newCell.SetCellValue(doubV);
                            break;
                        case "System.DBNull"://空值处理
                            newCell.SetCellValue("");
                            break;
                        default:
                            newCell.SetCellValue("");
                            break;
                    }
                    newCell.CellStyle.Alignment = HorizontalAlignment.Center;//居中
                }
                #endregion

                rowIndex++;
            }
            using (MemoryStream ms = new MemoryStream())
            {
                workbook.Write(ms);
                ms.Flush();
                ms.Position = 0;
                return ms;
            }
        }

        /// <summary>
        /// 用于Web导出
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <param name="strFileName">文件名</param>
        public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName)
        {
            HttpContext curContext = HttpContext.Current;

            //设置编码和附件格式
            curContext.Response.ContentType = "application/vnd.ms-excel";
            curContext.Response.ContentEncoding = Encoding.UTF8;
            curContext.Response.Charset = "";
            curContext.Response.AppendHeader("Content-Disposition",
                "attachment;filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8));

            curContext.Response.BinaryWrite(Export(dtSource, strHeaderText).GetBuffer());
            curContext.Response.End();
        }

        /// <summary>
        /// 读取excel第一个sheet的内容到DataTable中
        /// 默认第一行为标头
        /// </summary>
        /// <param name="strFilePath">excel文档路径</param>
        /// <param name="sheetName">sheet名字（为空或NULL则不判断）</param>
        /// <returns></returns>
        public static DataTable Import(string strFilePath, string sheetName)
        {
            DataTable dt = new DataTable();

            IWorkbook hssfworkbook;
       
            using (FileStream file = new FileStream(strFilePath, FileMode.Open, FileAccess.Read))
            {
                if (strFilePath.ToLower() == ".xls")
                {
                    hssfworkbook = new HSSFWorkbook(file);
                }
                else
                {
                    hssfworkbook = new XSSFWorkbook(strFilePath);
                }
            }
            ISheet sheet = hssfworkbook.GetSheetAt(0);
            if (!string.IsNullOrEmpty(sheetName))
            {
                if (sheet.SheetName != sheetName)
                {    
                    return null;//立即终止
                }
            }
            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
            

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

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

            for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
            {
                IRow row = sheet.GetRow(i);
                if (row == null) continue;//过滤空行

                DataRow dataRow = dt.NewRow();
                for (int j = row.FirstCellNum; j < cellCount; j++)
                {
                    if (row.GetCell(j) != null)
                        dataRow[j] = row.GetCell(j).ToString();
                }
                dt.Rows.Add(dataRow);
            }
            return dt;
        }
    }