Net操作Excel（终极方法NPOI）

用于记录
转载自：http://www.cnblogs.com/stone_w/archive/2012/08/02/2620528.html

Asp.net/C#操作Excel已经是老生长谈的事情了，可下面我说的这个NPOI操作Excel，应该是最好的方案了，没有之一，使用NPOI能够帮助开发者在没有安装微软Office的情况下读写Office 97-2003的文件，支持的文件格式包括xls, doc, ppt等。NPOI是构建在POI 3.x版本之上的，它可以在没有安装Office的情况下对Word/Excel文档进行读写操作。方法先去官网：http://npoi.codeplex.com/下载需要引入dll（可以选择.net2.0或者.net4.0的dll），然后在网站中添加引用。Asp.Net导出代码：复制代码NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();NPOI.SS.UserModel.ISheet sheet = book.CreateSheet("test_01");// 第一列NPOI.SS.UserModel.IRow row = sheet.CreateRow(0);row.CreateCell(0).SetCellValue("第一列第一行");// 第二列NPOI.SS.UserModel.IRow row2 = sheet.CreateRow(1);row2.CreateCell(0).SetCellValue("第二列第一行");// ...// 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={0}.xls", DateTime.Now.ToString("yyyyMMddHHmmssfff")));Response.BinaryWrite(ms.ToArray());book = null;ms.Close();ms.Dispose();复制代码Asp.Net导入代码：复制代码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  复制代码 C#导出Excel：复制代码public static void WriteExcel(DataTable dt, string filePath){    if (!string.IsNullOrEmpty(filePath) && null != dt && dt.Rows.Count > 0)    {        NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();        NPOI.SS.UserModel.ISheet sheet = book.CreateSheet(dt.TableName);        NPOI.SS.UserModel.IRow 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.IRow row2 = sheet.CreateRow(i + 1);            for (int j = 0; j < dt.Columns.Count; j++)            {                row2.CreateCell(j).SetCellValue(Convert.ToString(dt.Rows[i][j]));            }        }        // 写入到客户端          using (System.IO.MemoryStream ms = new System.IO.MemoryStream())        {            book.Write(ms);            using (FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.Write))            {                byte[] data = ms.ToArray();                fs.Write(data, 0, data.Length);                fs.Flush();            }            book = null;        }    }}