C# NPOI导出Excel和EPPlus导出Excel比较

系统中经常会使用导出Excel的功能。

之前使用的是NPOI，但是导出数据行数多就报内存溢出。

最近看到EPPlus可以用来导出Excel，就自己测了下两者导出上的差异。

NPIO官网地址：http://npoi.codeplex.com/

EPPlus官网地址：http://epplus.codeplex.com/

添加NPOI、EPPlus类库dll使用的是NuGet添加。

在类库References右键Manage NuGet Packages...，之后选择添加对应的dll。

测试结果显示，相同数据结构的数据，EPPlus的导出能力比NPOI强。

20列，NPOI能导出4万数据，导出5万数据时报内存溢出。

EPPlus能导出20万以上数据，导出23万测试时内存溢出。

NPOI导出：

 private static MemoryStream ExportXlsx(DataTable dt)
         {
             XSSFWorkbook workbook = new XSSFWorkbook();
             ISheet sheet = null;

             int headRowIndex = ;
             string sheetName = "Sheet1";
             if (!string.IsNullOrEmpty(dt.TableName))
             {
                 sheetName = dt.TableName;
             }
             sheet = workbook.CreateSheet(sheetName);
             int rowIndex = ;

             #region 列头及样式
             {
                 XSSFRow headerRow = (XSSFRow)sheet.CreateRow(headRowIndex);

                 ICellStyle headStyle = workbook.CreateCellStyle();
                 headStyle.Alignment = HorizontalAlignment.Center;
                 IFont font = workbook.CreateFont();
                 font.FontHeightInPoints = ;
                 font.Boldweight = ;
                 headStyle.SetFont(font);

                 foreach (DataColumn column in dt.Columns)
                 {
                     headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                     headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
                 }
             }
             #endregion

             #region 填充内容

             foreach (DataRow row in dt.Rows)
             {
                 rowIndex++;
                 XSSFRow dataRow = (XSSFRow)sheet.CreateRow(rowIndex);
                 foreach (DataColumn column in dt.Columns)
                 {
                     string drValue = row[column].ToString();
                     dataRow.CreateCell(column.Ordinal).SetCellValue(drValue);
                 }
             }
             #endregion

             MemoryStream ms = new MemoryStream();

             workbook.Write(ms);
             ms.Flush();

             return ms;
         }

         public static void ExportXlsxByWeb(DataTable dt, string strFileName)
         {

             HttpContext curContext = HttpContext.Current;

             MemoryStream ms = ExportXlsx(dt);

             curContext.Response.AppendHeader("Content-Disposition",
                 "attachment;filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8) + ".xlsx");
             curContext.Response.AddHeader("Content-Length", ms.ToArray().Length.ToString());
             curContext.Response.ContentEncoding = Encoding.UTF8;

             curContext.Response.BinaryWrite(ms.ToArray());
             ms.Close();
             ms.Dispose();
             curContext.Response.End();

         }

EPPlus导出：

 /// <summary>
         /// 使用EPPlus导出Excel(xlsx)
         /// </summary>
         /// <param name="sourceTable">数据源</param>
         /// <param name="strFileName">xlsx文件名(不含后缀名)</param>
         public static void ExportByEPPlus(DataTable sourceTable, string strFileName)
         {
             using (ExcelPackage pck = new ExcelPackage())
             {
                 //Create the worksheet
                 string sheetName = string.IsNullOrEmpty(sourceTable.TableName) ? "Sheet1" : sourceTable.TableName;
                 ExcelWorksheet ws = pck.Workbook.Worksheets.Add(sheetName);

                 //Load the datatable into the sheet, starting from cell A1. Print the column names on row 1
                 ws.Cells["A1"].LoadFromDataTable(sourceTable, true);

                 //Format the row
                 ExcelBorderStyle borderStyle = ExcelBorderStyle.Thin;
                 Color borderColor = Color.FromArgb(, , );

                 using (ExcelRange rng = ws.Cells[, , sourceTable.Rows.Count + , sourceTable.Columns.Count])
                 {
                     rng.Style.Font.Name = "宋体";
                     rng.Style.Font.Size = ;
                     rng.Style.Fill.PatternType = ExcelFillStyle.Solid;                      //Set Pattern for the background to Solid
                     rng.Style.Fill.BackgroundColor.SetColor(Color.FromArgb(, , ));

                     rng.Style.Border.Top.Style = borderStyle;
                     rng.Style.Border.Top.Color.SetColor(borderColor);

                     rng.Style.Border.Bottom.Style = borderStyle;
                     rng.Style.Border.Bottom.Color.SetColor(borderColor);

                     rng.Style.Border.Right.Style = borderStyle;
                     rng.Style.Border.Right.Color.SetColor(borderColor);
                 }

                 //Format the header row
                 using (ExcelRange rng = ws.Cells[, , , sourceTable.Columns.Count])
                 {
                     rng.Style.Font.Bold = true;
                     rng.Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;
                     rng.Style.Fill.BackgroundColor.SetColor(Color.FromArgb(, , ));  //Set color to dark blue
                     rng.Style.Font.Color.SetColor(Color.FromArgb(, , ));
                 }

                 //Write it back to the client
                 HttpContext.Current.Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                 HttpContext.Current.Response.AddHeader("content-disposition", string.Format("attachment;  filename={0}.xlsx", HttpUtility.UrlEncode(strFileName, Encoding.UTF8)));
                 HttpContext.Current.Response.ContentEncoding = Encoding.UTF8;

                 HttpContext.Current.Response.BinaryWrite(pck.GetAsByteArray());
                 HttpContext.Current.Response.End();
             }
         }

程序生成DataTable，20列，内容如下图

电脑配置：

测试结果：

条数	NPOI	EPPlus
10000	成功生成	成功生成
20000	成功生成	成功生成
30000	成功生成	成功生成
40000	成功生成	成功生成
50000	失败	成功生成
100000	失败	成功生成
200000	失败	成功生成
230000	失败	失败