lenlenya
3/22/2018 - 9:35 AM

利用NPOI导入导出Excel

利用NPOI导入导出Excel

## ASP.Net MVC利用NPOI导入导出Excel

因近期项目遇到所以记录一下:

(Action一定要用FileResult)

        /// <summary>
        /// 批量导出本校第一批派位学生
        /// </summary>
        /// <returns></returns>
        public FileResult ExportStu2()
        {
            string schoolname = "401";
            //创建Excel文件的对象
            NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
            //添加一个sheet
            NPOI.SS.UserModel.ISheet sheet1 = book.CreateSheet("Sheet1");
            //获取list数据
            List<TB_STUDENTINFOModel> listRainInfo = m_BLL.GetSchoolListAATQ(schoolname);
            //给sheet1添加第一行的头部标题
            NPOI.SS.UserModel.IRow row1 = sheet1.CreateRow(0);
            row1.CreateCell(0).SetCellValue("电脑号");
            row1.CreateCell(1).SetCellValue("姓名");
            //将数据逐步写入sheet1各个行
            for (int i = 0; i < listRainInfo.Count; i++)
            {
                NPOI.SS.UserModel.IRow rowtemp = sheet1.CreateRow(i + 1);
                rowtemp.CreateCell(0).SetCellValue(listRainInfo[i].ST_CODE.ToString());
                rowtemp.CreateCell(1).SetCellValue(listRainInfo[i].ST_NAME.ToString());
            }
            // 写入到客户端 
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            book.Write(ms);
            ms.Seek(0, SeekOrigin.Begin);
            return File(ms, "application/vnd.ms-excel", "第一批电脑派位生名册.xls");
        }

前台直接写就可实现:

`@Html.ActionLink("点击导出名册", "ExportStu2")`

下面说一下导出:

首先说一些前台吧,mvc上传注意必须加 `new { enctype = "multipart/form-data" }:`

        <div>
            @using(@Html.BeginForm("ImportStu", "ProSchool", ormMethod.Post, new { enctype = "multipart/form-data" }))
              {
              <text>选择上传文件:(工作表名为“Sheet1”,“电脑号”在A1单元格。)/text>
              <input name="file" type="file" id="file" />
              <input type="submit" name="Upload" value="批量导入第一批电脑派名册" />
              }
        </div>

后台实现:只传路径得出DataTable:

        /// <summary>
        /// Excel导入
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns></returns>
        public DataTable ImportExcelFile(string filePath)
        {
            HSSFWorkbook hssfworkbook;
            #region//初始化信息
            try
            {
                using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
                {
                    hssfworkbook = new HSSFWorkbook(file);
                }
            }
            catch (Exception e)
            {
                throw e;
            }
            #endregion

            using (NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0))
            {
                DataTable table = new DataTable();
                IRow headerRow = sheet.GetRow(0);//第一行为标题行
                int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
                int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1

                //handling header.
                for (int i = headerRow.FirstCellNum; i < cellCount; i++)
                {
                    DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
                    table.Columns.Add(column);
                }
                for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)
                {
                    IRow row = sheet.GetRow(i);
                    DataRow dataRow = table.NewRow();

                    if (row != null)
                    {
                        for (int j = row.FirstCellNum; j < cellCount; j++)
                        {
                            if (row.GetCell(j) != null)
                                dataRow[j] = GetCellValue(row.GetCell(j));
                        }
                    }

                    table.Rows.Add(dataRow);
                }
                return table;
            }
            
        }

补充一个类

        /// <summary>
        /// 根据Excel列类型获取列的值
        /// </summary>
        /// <param name="cell">Excel列</param>
        /// <returns></returns>
        private static string GetCellValue(ICell cell)
        {
            if (cell == null)
                return string.Empty;
            switch (cell.CellType)
            {
                case CellType.BLANK:
                    return string.Empty;
                case CellType.BOOLEAN:
                    return cell.BooleanCellValue.ToString();
                case CellType.ERROR:
                    return cell.ErrorCellValue.ToString();
                case CellType.NUMERIC:
                case CellType.Unknown:
                default:
                    return cell.ToString();//This is a trick to get the correct value of the cell. NumericCellValue will return a numeric value no matter the cell value is a date or a number
                case CellType.STRING:
                    return cell.StringCellValue;
                case CellType.FORMULA:
                    try
                    {
                        HSSFFormulaEvaluator e = new HSSFFormulaEvaluator(cell.Sheet.Workbook);
                        e.EvaluateInCell(cell);
                        return cell.ToString();
                    }
                    catch
                    {
                        return cell.NumericCellValue.ToString();
                    }
            }
        }

得到DataTable后,就想怎么操作就怎么操作了