asp.net DataTable导出 excel的方法记录（第三方）

官网：http://npoi.codeplex.com/

简单应用，主要是可以实现我们想要的简单效果，呵呵

需要引入dll，可以在官网下载，也可在下面下载

protected void getExcel(DataTable dt)
   {
       NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
       NPOI.SS.UserModel.Sheet sheet = book.CreateSheet("test_01");
       NPOI.SS.UserModel.Row row = sheet.CreateRow(0);
       for (int i = 0; i < dt.Columns.Count; i++)
       {
           row.CreateCell(i).SetCellValue(dt.Columns[i].ColumnName);
       }

       for (int i = 0; i < dt.Rows.Count; i++)
       {
           NPOI.SS.UserModel.Row row2 = sheet.CreateRow(i + 1);
           for (int j = 0; j < dt.Columns.Count; j++)
               row2.CreateCell(j).SetCellValue(dt.Rows[i][j].ToString());
       }


       //写入到客户端
       System.IO.MemoryStream ms = new System.IO.MemoryStream();
       book.Write(ms);
       Response.AddHeader("Content-Disposition", string.Format("attachment; filename=EmptyWorkbook.xls"));
       Response.BinaryWrite(ms.ToArray());
       book = null;
       ms.Close();
       ms.Dispose();

   }

EXCEL导入

HSSFWorkbook hssfworkbook;
        #region
        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.Sheet 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.Cell cell = row.GetCell(i);


                    if (cell == null)
                    {
                        dr[i] = null;
                    }
                    else
                    {
                        dr[i] = cell.ToString();
                    }
                }
                dt.Rows.Add(dr);
            }
           return dt;
        }
        #endregion

这样就可以读取一个EXCEL的文件了返回一个Datatable