using System;  using System.Data;  using System.IO;  using System.Text;  using System.Web;  using NPOI.HPSF;  using NPOI.HSSF.UserModel;  using NPOI.SS.UserModel;    public class ExcelHelper  {      /// <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>      /// <param name="strSheetName">工作表名称</param>      /// <Author>柳永法 http://www.yongfa365.com/ 2010-5-8 22:21:41</Author>         public static void Export(DataTable dtSource, string strHeaderText, string strFileName, string strSheetName, string[] oldColumnNames, string[] newColumnNames)      {          if (strSheetName == "")          {              strSheetName = "Sheet";          }          using (MemoryStream ms = Export(dtSource, strHeaderText, strSheetName, oldColumnNames, newColumnNames))          {              using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))              {                  byte[] data =http://www.mamicode.com/ 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>         /// <param name="strSheetName">工作表名称</param>      /// <Author>柳永法 http://www.yongfa365.com/ 2010-5-8 22:21:41</Author>         public static MemoryStream Export(DataTable dtSource, string strHeaderText, string strSheetName, string[] oldColumnNames, string[] newColumnNames)      {          if (oldColumnNames.Length != newColumnNames.Length)          {              return new MemoryStream();          }          HSSFWorkbook workbook = new HSSFWorkbook();          //HSSFSheet sheet = workbook.CreateSheet();// workbook.CreateSheet();          ISheet sheet = workbook.CreateSheet(strSheetName);           #region 右击文件 属性信息          {              DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();              dsi.Company = "http://....../";              workbook.DocumentSummaryInformation = dsi;                SummaryInformation si = PropertySetFactory.CreateSummaryInformation();              if (HttpContext.Current.Session["realname"] != null)              {                  si.Author = HttpContext.Current.Session["realname"].ToString();              }              else              {                  if (HttpContext.Current.Session["username"] != null)                  {                      si.Author = HttpContext.Current.Session["username"].ToString();                  }              }                                       //填加xls文件作者信息                 si.ApplicationName = "NPOI";            //填加xls文件创建程序信息                 si.LastAuthor = "OA系统";           //填加xls文件最后保存者信息                 si.Comments = "OA系统自动创建文件";      //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            ICellStyle dateStyle = workbook.CreateCellStyle();          IDataFormat format = workbook.CreateDataFormat();          dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");           #region 取得列宽          int[] arrColWidth = new int[oldColumnNames.Length];          for (int i = 0; i < oldColumnNames.Length; i++)          {              arrColWidth[i] = Encoding.GetEncoding(936).GetBytes(newColumnNames[i]).Length;          }          /*         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 < oldColumnNames.Length; j++)              {                  int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][oldColumnNames[j]].ToString()).Length;                  if (intTemp > arrColWidth[j])                  {                      arrColWidth[j] = intTemp;                  }              }              /*             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;                 }             }              * */          }          #endregion          int rowIndex = 0;            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)                  {                      sheet = workbook.CreateSheet(strSheetName + ((int)rowIndex/65535).ToString());                  }                   #region 表头及样式                  {                      IRow headerRow = sheet.CreateRow(0);                      headerRow.HeightInPoints = 25;                      headerRow.CreateCell(0).SetCellValue(strHeaderText);                        ICellStyle headStyle = workbook.CreateCellStyle();                      headStyle.Alignment = HorizontalAlignment.CENTER;                      IFont font = workbook.CreateFont();                      font.FontHeightInPoints = 20;                      font.Boldweight = 700;                      headStyle.SetFont(font);                        headerRow.GetCell(0).CellStyle = headStyle;                      //sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));                      sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, dtSource.Columns.Count - 1));                  }                  #endregion                    #region 列头及样式                  {                      //HSSFRow headerRow = sheet.CreateRow(1);                      IRow headerRow = sheet.CreateRow(1);                        ICellStyle headStyle = workbook.CreateCellStyle();                      headStyle.Alignment = HorizontalAlignment.CENTER;                      IFont font = workbook.CreateFont();                      font.FontHeightInPoints = 10;                      font.Boldweight = 700;                      headStyle.SetFont(font);                        for (int i = 0; i < oldColumnNames.Length; i++)                      {                          headerRow.CreateCell(i).SetCellValue(newColumnNames[i]);                          headerRow.GetCell(i).CellStyle = headStyle;                          //设置列宽                          sheet.SetColumnWidth(i, (arrColWidth[i] + 1) * 256);                      }                      /*                     foreach (DataColumn column in dtSource.Columns)                     {                         headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);                         headerRow.GetCell(column.Ordinal).CellStyle = headStyle;                          //设置列宽                            sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);                     }                      * */                  }                  #endregion                    rowIndex = 2;              }              #endregion                #region 填充内容              IRow dataRow = sheet.CreateRow(rowIndex);              //foreach (DataColumn column in dtSource.Columns)              for(int i=0;i<oldColumnNames.Length;i++)              {                  ICell newCell = dataRow.CreateCell(i);                    string drValue =http://www.mamicode.com/ row[oldColumnNames[i]].ToString();                    switch (dtSource.Columns[oldColumnNames[i]].DataType.ToString())                  {                      case "System.String"://字符串类型                             newCell.SetCellValue(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;                  }                }              #endregion                rowIndex++;          }              using (MemoryStream ms = new MemoryStream())          {              workbook.Write(ms);              ms.Flush();              ms.Position = 0;                //sheet.Dispose();              sheet = null;              workbook = null;              //workbook.Dispose();//一般只用写这一个就OK了，他会遍历并释放所有资源，但当前版本有问题所以只释放sheet                 return ms;          }      }          /// <summary>         /// WEB导出DataTable到Excel         /// </summary>         /// <param name="dtSource">源DataTable</param>         /// <param name="strHeaderText">表头文本</param>         /// <param name="strFileName">文件名</param>         /// <Author>柳永法 http://www.yongfa365.com/ 2010-5-8 22:21:41</Author>         public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName)      {          ExportByWeb(dtSource, strHeaderText, strFileName, "sheet");      }        /// <summary>      /// WEB导出DataTable到Excel      /// </summary>      /// <param name="dtSource">源DataTable</param>      /// <param name="strHeaderText">表头文本</param>      /// <param name="strFileName">输出文件名，包含扩展名</param>      /// <param name="oldColumnNames">要导出的DataTable列数组</param>      /// <param name="newColumnNames">导出后的对应列名</param>      public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName, string[] oldColumnNames, string[] newColumnNames)      {          ExportByWeb(dtSource, strHeaderText, strFileName, "sheet",oldColumnNames,newColumnNames);      }        /// <summary>      /// WEB导出DataTable到Excel      /// </summary>      /// <param name="dtSource">源DataTable</param>      /// <param name="strHeaderText">表头文本</param>      /// <param name="strFileName">输出文件名</param>      /// <param name="strSheetName">工作表名称</param>      public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName, string strSheetName)      {          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));            //生成列          string columns = "";          for (int i = 0; i < dtSource.Columns.Count; i++)          {              if (i > 0)              {                  columns += ",";              }              columns += dtSource.Columns[i].ColumnName;          }            curContext.Response.BinaryWrite(Export(dtSource, strHeaderText,strSheetName,columns.Split(‘,‘),columns.Split(‘,‘)).GetBuffer());          curContext.Response.End();        }        /// <summary>      /// 导出DataTable到Excel      /// </summary>      /// <param name="dtSource">要导出的DataTable</param>      /// <param name="strHeaderText">标题文字</param>      /// <param name="strFileName">文件名，包含扩展名</param>      /// <param name="strSheetName">工作表名</param>      /// <param name="oldColumnNames">要导出的DataTable列数组</param>      /// <param name="newColumnNames">导出后的对应列名</param>      public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName, string strSheetName, string[] oldColumnNames, string[] newColumnNames)      {          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, strSheetName,oldColumnNames,newColumnNames).GetBuffer());          curContext.Response.End();      }        /// <summary>读取excel         /// 默认第一行为表头，导入第一个工作表      /// </summary>         /// <param name="strFileName">excel文档路径</param>         /// <returns></returns>         public static DataTable Import(string strFileName)      {          DataTable dt = new DataTable();            HSSFWorkbook hssfworkbook;          using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))          {              hssfworkbook = new HSSFWorkbook(file);          }          ISheet sheet = hssfworkbook.GetSheetAt(0);          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);              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;      }      /// <summary>      /// 从Excel中获取数据到DataTable      /// </summary>      /// <param name="strFileName">Excel文件全路径(服务器路径)</param>      /// <param name="SheetName">要获取数据的工作表名称</param>      /// <param name="HeaderRowIndex">工作表标题行所在行号(从0开始)</param>      /// <returns></returns>      public static DataTable RenderDataTableFromExcel(string strFileName, string SheetName, int HeaderRowIndex)      {          using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))          {              IWorkbook workbook = new HSSFWorkbook(file);              return RenderDataTableFromExcel(workbook, SheetName, HeaderRowIndex);          }      }        /// <summary>      /// 从Excel中获取数据到DataTable      /// </summary>      /// <param name="strFileName">Excel文件全路径(服务器路径)</param>      /// <param name="SheetIndex">要获取数据的工作表序号(从0开始)</param>      /// <param name="HeaderRowIndex">工作表标题行所在行号(从0开始)</param>      /// <returns></returns>      public static DataTable RenderDataTableFromExcel(string strFileName, int SheetIndex, int HeaderRowIndex)      {          using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))          {              IWorkbook workbook = new HSSFWorkbook(file);              string SheetName = workbook.GetSheetName(SheetIndex);              return RenderDataTableFromExcel(workbook, SheetName, HeaderRowIndex);          }      }        /// <summary>      /// 从Excel中获取数据到DataTable      /// </summary>      /// <param name="ExcelFileStream">Excel文件流</param>      /// <param name="SheetName">要获取数据的工作表名称</param>      /// <param name="HeaderRowIndex">工作表标题行所在行号(从0开始)</param>      /// <returns></returns>      public static DataTable RenderDataTableFromExcel(Stream ExcelFileStream, string SheetName, int HeaderRowIndex)      {          IWorkbook workbook = new HSSFWorkbook(ExcelFileStream);          ExcelFileStream.Close();          return RenderDataTableFromExcel(workbook, SheetName, HeaderRowIndex);      }        /// <summary>      /// 从Excel中获取数据到DataTable      /// </summary>      /// <param name="ExcelFileStream">Excel文件流</param>      /// <param name="SheetIndex">要获取数据的工作表序号(从0开始)</param>      /// <param name="HeaderRowIndex">工作表标题行所在行号(从0开始)</param>      /// <returns></returns>      public static DataTable RenderDataTableFromExcel(Stream ExcelFileStream, int SheetIndex, int HeaderRowIndex)      {          IWorkbook workbook = new HSSFWorkbook(ExcelFileStream);          ExcelFileStream.Close();          string SheetName = workbook.GetSheetName(SheetIndex);          return RenderDataTableFromExcel(workbook, SheetName, HeaderRowIndex);      }        /// <summary>      /// 从Excel中获取数据到DataTable      /// </summary>      /// <param name="workbook">要处理的工作薄</param>      /// <param name="SheetName">要获取数据的工作表名称</param>      /// <param name="HeaderRowIndex">工作表标题行所在行号(从0开始)</param>      /// <returns></returns>      public static DataTable RenderDataTableFromExcel(IWorkbook workbook, string SheetName, int HeaderRowIndex)      {          ISheet sheet = workbook.GetSheet(SheetName);          DataTable table = new DataTable();          try          {              IRow headerRow = sheet.GetRow(HeaderRowIndex);              int cellCount = headerRow.LastCellNum;                for (int i = headerRow.FirstCellNum; i < cellCount; i++)              {                  DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);                  table.Columns.Add(column);              }                int rowCount = sheet.LastRowNum;               #region 循环各行各列,写入数据到DataTable              for (int i = (sheet.FirstRowNum + 1); i < sheet.LastRowNum; i++)              {                  IRow row = sheet.GetRow(i);                  DataRow dataRow = table.NewRow();                  for (int j = row.FirstCellNum; j < cellCount; j++)                  {                      ICell cell = row.GetCell(j);                      if (cell == null)                      {                          dataRow[j] = null;                      }                      else                      {                          //dataRow[j] = cell.ToString();                          switch (cell.CellType)                          {                              case CellType.BLANK:                                  dataRow[j] = null;                                  break;                              case CellType.BOOLEAN:                                  dataRow[j] = cell.BooleanCellValue;                                  break;                              case CellType.NUMERIC:                                  dataRow[j] = cell.ToString();                                  break;                              case CellType.STRING:                                  dataRow[j] = cell.StringCellValue;                                  break;                              case CellType.ERROR:                                  dataRow[j] = cell.ErrorCellValue;                                  break;                              case CellType.FORMULA:                              default:                                  dataRow[j] = "=" + cell.CellFormula;                                  break;                          }                      }                  }                  table.Rows.Add(dataRow);                  //dataRow[j] = row.GetCell(j).ToString();              }              #endregion          }          catch (System.Exception ex)          {              table.Clear();              table.Columns.Clear();              table.Columns.Add("出错了");              DataRow dr = table.NewRow();              dr[0] = ex.Message;              table.Rows.Add(dr);              return table;          }          finally          {              //sheet.Dispose();              workbook = null;              sheet = null;          }          #region 清除最后的空行          for (int i = table.Rows.Count - 1; i > 0; i--)          {              bool isnull = true;              for (int j = 0; j < table.Columns.Count; j++)              {                  if (table.Rows[i][j] != null)                  {                      if (table.Rows[i][j].ToString() != "")                      {                          isnull = false;                          break;                      }                  }              }              if (isnull)              {                  table.Rows[i].Delete();              }          }          #endregion          return table;      }  }