使用NPOI导出数据库到Excel文件

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Web;
using  System.Data;
using  System.Data.SqlClient;
using  NPOI.HSSF.UserModel;


namespace  ExportToExcelWeb
{
     ///   <summary>
     ///  ExportToExcel 的摘要说明
     ///   </summary>
     public   class  ExportToExcel : IHttpHandler
    {

         public   void  ProcessRequest(HttpContext context)
        {
            context.Response.ContentType  =   " application/x-excel " ;
             string  fileName  =  HttpUtility.UrlEncode( " 数据库文备份.xls " );
            context.Response.AddHeader( " Content-Disposition " ,  " attachment; fileName= "   +  fileName);   // 添加http协议报文;

            HSSFWorkbook workbook  =   new  HSSFWorkbook();  // 创建一个xls；
            HSSFSheet sheet  =  workbook.CreateSheet();  // 创建一个Sheet页

             string  connectString  =   @" server=localhost\sql2008;database=MyBlog; uid=sa; pwd=sql2008 " ;
            SqlConnection connection  =   new  SqlConnection(connectString);
            connection.Open();

             using  (IDbCommand cmd  =  connection.CreateCommand())  // 接口编徎;
            {
                cmd.CommandText  =   " select * from Users " ;
                 using  (IDataReader reader  =  cmd.ExecuteReader())
                {
                     int  rowsNum  =   0 ;   // 行号
                     while  (reader.Read())
                    {
                         // 根据字段名找出ID
                         string  LoginId  =  reader.GetString(reader.GetOrdinal( " LoginId " ));
                         string  LoginPwd  =  reader.GetString(reader.GetOrdinal( " LoginPwd " ));
                         string  Name  =  reader.GetString(reader.GetOrdinal( " Name " ));
                         string  QQ  =  reader.GetString(reader.GetOrdinal( " QQ " ));
                         string  Mail  =  reader.GetString(reader.GetOrdinal( " Mail " ));

                         /* *****************以上代码对应数据库表中的字段******************** */

                        HSSFRow row  =  sheet.CreateRow(rowsNum);
                        row.CreateCell( 0 , HSSFCell.CELL_TYPE_STRING).SetCellValue(LoginId);
                        row.CreateCell( 1 , HSSFCell.CELL_TYPE_STRING).SetCellValue(LoginPwd);
                        row.CreateCell( 2 , HSSFCell.CELL_TYPE_STRING).SetCellValue(Name);
                        row.CreateCell( 3 , HSSFCell.CELL_TYPE_STRING).SetCellValue(QQ);
                        row.CreateCell( 4 , HSSFCell.CELL_TYPE_STRING).SetCellValue(Mail);

                         /* *****************以上代码对应Excel文件的列*********************** */
                        rowsNum ++ ;
                    }
                }
            }

            workbook.Write(context.Response.OutputStream);   // 输出到流中

        }

         public   bool  IsReusable
        {
             get
            {
                 return   false ;
            }
        }
    }
}