NPOI大数据量多个sheet导出源码（原）

代码如下：

   #region  NPOI大数据量多个sheet导出

         /// <summary>
         /// 大数据量多个sheet导出
         /// </summary>
         /// <typeparam name="T">数据源实体类</typeparam>
         /// <param name="objList">数据源</param>
         /// <param name="fileName">文件名称</param>
         /// <param name="btyBytes">导出数据流</param>
         /// <param name="columnInfo">显示列对应数据字典</param>
         /// <param name="listCount">每个sheet包含数据条数</param>
         /// <returns></returns>
         public static bool ExportExcelTest<T>(List<T> objList, string fileName, ref byte[] btyBytes,
 　　　　　　　　　　　　　　　　　　　　　　　　　　Dictionary<string, string> columnInfo = null,int listCount=)
         {
             bool bResult = false;
             //在内存中生成一个Excel文件：
             HSSFWorkbook book = new HSSFWorkbook();
             if (objList != null && objList.Count > )
             {
                 double sheetCount = Math.Ceiling((double)objList.Count / listCount);
                 for (int i = ; i < sheetCount; i++)
                 {
                     ISheet sheet = null;
                     sheet = book.CreateSheet("sheet" + i);
                     sheet.DefaultRowHeight =  * ;
                     List<T> list = new List<T>();
                     list = objList.Skip<T>(listCount * i).Take<T>(listCount).ToList();

                     int rowIndex = ;
                     int StartColIndex = ;
                     int colIndex = StartColIndex;

                     //创建表头样式
                     ICellStyle style = book.CreateCellStyle();
                     style.Alignment = HorizontalAlignment.Center;
                     style.WrapText = true;
                     IFont font = book.CreateFont();
                     font.FontHeightInPoints = ;
                     font.Boldweight = (short)NPOI.SS.UserModel.FontBoldWeight.Bold;
                     font.FontName = "简体中文";
                     style.SetFont(font);//HEAD 样式

                     Type myType = null;
                     myType = objList[].GetType();
                     //根据反射从传递进来的属性名信息得到要显示的属性
                     List<PropertyInfo> myPro = new List<PropertyInfo>();
                     PropertyInfo[] properties = myType.GetProperties();

                     #region 定义表头
                     int m = ;
                     if (columnInfo != null)
                     {
                         var rowheader = sheet.CreateRow();
                         rowheader.Height = rowheader.Height =  * ;
                         foreach (string cName in columnInfo.Keys)
                         {
                             PropertyInfo p = myType.GetProperty(cName);
                             if (p != null)
                             {
                                 myPro.Add(p);
                                 rowheader.CreateCell(m).SetCellValue(columnInfo[cName]);
                                 m++;
                             }
                         }
                     }
                     #endregion
                     #region 定义表体并赋值
                     //如果没有找到可用的属性则结束
                     if (myPro.Count == ) { return bResult; }
                     foreach (T obj in list)
                     {
                         int n = ;
                         if (sheet != null)
                         {
                             rowIndex++;
                             var sheetrow = sheet.CreateRow(rowIndex);
                             sheetrow.Height = sheetrow.Height =  * ;
                             foreach (PropertyInfo p in myPro)
                             {
                                 dynamic val = p.GetValue(obj, null) ?? "";
                                 string valtype = val.GetType().ToString();
                                 if (valtype.ToLower().IndexOf("decimal", StringComparison.Ordinal) > -)
                                 {
                                     val = Convert.ToDouble(val);
                                 }
                                 else if (valtype.ToLower().IndexOf("datetime", StringComparison.Ordinal) > -)
                                 {
                                     val = val.ToString("yyyy-MM-dd HH:mm:ss");
                                     if (val.Equals("0001-01-01 00:00:00"))
                                     {
                                         val = "";
                                     }
                                 }
                                 sheetrow.CreateCell(n).SetCellValue(val);
                                 n++;
                             }
                         }

                     }
                     #endregion
                 }
             }
             else
             {
                 //在工作薄中建立工作表
                 HSSFSheet sheet = book.CreateSheet() as HSSFSheet;
                 sheet.SetColumnWidth(,  * );
                 if (sheet != null) sheet.CreateRow().CreateCell().SetCellValue("暂无数据！");
             }

             try
             {
                 HttpResponse rs = System.Web.HttpContext.Current.Response;
                 rs.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
                 rs.AppendHeader("Content-Disposition", "attachment;filename=" + fileName);
                 rs.ContentType = "application/ms-excel";
                 using (MemoryStream ms = new MemoryStream())
                 {
                     book.Write(ms);
                     rs.BinaryWrite(ms.ToArray());
                     ms.Flush();
                 }
             }
             catch (SystemException ex)
             {
                 LogHelper.Write(ex);
             }
             catch (ApplicationException ex)
             {
                 LogHelper.Write(ex);
             }
             return bResult;
         }

         #endregion