读写Excle,不用office环境

1.下载NPOI.dll,并添加引用

 

2.ExcelHelper帮助类,以下为读写的参照方法

        HSSFWorkbook hssfworkbook;  

        #region  导入Excel 返回Table

        public DataTable ImportExcelFile(string filePath)

        {

            #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



            NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0);

            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

            DataTable dt = new DataTable();

            for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)

            {

                dt.Columns.Add(Convert.ToChar(((int)'A') + j).ToString());

            }

            while (rows.MoveNext())

            {

                HSSFRow row = (HSSFRow)rows.Current;

                DataRow dr = dt.NewRow();

                for (int i = 0; i < row.LastCellNum; i++)

                {

                    NPOI.SS.UserModel.ICell cell = row.GetCell(i);

                    if (cell == null)

                    {

                        dr[i] = null;

                    }

                    else

                    {

                        dr[i] = cell.ToString();

                    }

                }

                dt.Rows.Add(dr);

            }

            return dt;

        }

        #endregion



        #region 导出excel

        //Datatable导出Excel

        public   MemoryStream  GridToExcelByNPOI(DataTable dt)

        {

            try

            {

                HSSFWorkbook workbook = new HSSFWorkbook();

                ISheet sheet = workbook.CreateSheet("Sheet1");



                ICellStyle HeadercellStyle = workbook.CreateCellStyle();

                HeadercellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;

                HeadercellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;

                HeadercellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;

                HeadercellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;

                HeadercellStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;

                //字体

                NPOI.SS.UserModel.IFont headerfont = workbook.CreateFont();

                headerfont.Boldweight = (short)FontBoldWeight.Bold;

                HeadercellStyle.SetFont(headerfont);





                //用column name 作为列名

                int icolIndex = 0;

                IRow headerRow = sheet.CreateRow(0);

                foreach (DataColumn item in dt.Columns)

                {

                    ICell cell = headerRow.CreateCell(icolIndex);

                    cell.SetCellValue(item.ColumnName);

                    cell.CellStyle = HeadercellStyle;

                    icolIndex++;

                }



                ICellStyle cellStyle = workbook.CreateCellStyle();



                //为避免日期格式被Excel自动替换，所以设定 format 为 『@』 表示一率当成text來看

                cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("@");

                cellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;

                cellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;

                cellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;

                cellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;





                NPOI.SS.UserModel.IFont cellfont = workbook.CreateFont();

                cellfont.Boldweight = (short)FontBoldWeight.Normal;

                cellStyle.SetFont(cellfont);



                //建立内容行

                int iRowIndex = 1;

                int iCellIndex = 0;

                foreach (DataRow Rowitem in dt.Rows)

                {

                    IRow DataRow = sheet.CreateRow(iRowIndex);

                    foreach (DataColumn Colitem in dt.Columns)

                    {



                        ICell cell = DataRow.CreateCell(iCellIndex);

                        cell.SetCellValue(Rowitem[Colitem].ToString());

                        cell.CellStyle = cellStyle;

                        iCellIndex++;

                    }

                    iCellIndex = 0;

                    iRowIndex++;

                }



                //自适应列宽度

                for (int i = 0; i < icolIndex; i++)

                {

                    sheet.AutoSizeColumn(i);

                }



                //写Excel

                MemoryStream  ms = new MemoryStream ();

                workbook.Write(ms);

                ms.Flush();

                ms.Position = 0;



                return ms;

            }

            catch (Exception ex)

            {

                throw ex;

            }

        }

        #endregion