大批量快速导出Excel方法

我的方法不是使用微软的excel操作类，因为那种实在爆慢，一个个单元格循环写，实在太慢了。【不信朋友们可以试试】
而使用io写的话  半分钟都不用
我数据库数据量为：120000行 29列

技术要点:1.使用的是StreamWriter sw = new StreamWriter(path, false,Encoding.GetEncoding("gb2312"));最终生成文件
2.使用  StringBuilder sb = new StringBuilder();类把查询出来的数据组合为一句超长字符串一次性插入到excel中，
sb.Append(ds.Tables[0].Columns[k].ColumnName.ToString() + "\t");
注意，可不能漏了"\t" 这个是非常重要的！ 因为c# "\t"就等于 键盘上的Tab [朋友们可以试试：打开新的txt然后输入1按Tab，输入2按Tab，输入3按Tab保存，然后打开excel文件  把刚刚保存的txt文件拉进去打开你就发现原来。这样写的话1 2 3 会分别在每个单元格上的了。所以上面才使用 "\t"连起来数据库出来的那堆数据，这样一次性导进去，他们就会按照每个单元格来填充！]

方法如下（原文的代码）：

private  void  button1_Click( object  sender, EventArgs e)
        {
            saveFileDialog1.Title =  "保存的excel文件" ;
            saveFileDialog1.InitialDirectory =  "c:\\" ;
            saveFileDialog1.Filter =  "Excel97-2003 (*.xls)|*.xls|All Files (*.*)|*.*" ;
            saveFileDialog1.ShowDialog();
            if  (saveFileDialog1.FileName ==  ""  || saveFileDialog1.FileName ==  null )
            {
                MessageBox.Show( "文件名不能为空!" );
                return ;
            }
            string  path = saveFileDialog1.FileName;
            string  constr =  "Data Source=.;Initial Catalog=Exhibition;User ID=sa;Password=" ;
            string  sql = GetStrSql();
            DataSet ds= new  DataSet();
            using  (SqlConnection con =  new  SqlConnection(constr))
            {
                SqlDataAdapter da =  new  SqlDataAdapter(sql, con);
                da.Fill(ds);
            }
            if  (ds ==  null )
            {
                MessageBox.Show( "数据获取有误!" );
                return ;
            }
            WriteExcel(ds, path);
        }

 public  void  WriteExcel(DataSet ds,  string  path)
        {
            try
            {
                long  totalCount = ds.Tables[0].Rows.Count;
                lblTip.Text =  "共有"  + totalCount +  "条数据。" ;
                Thread.Sleep(1000);
                long  rowRead = 0;
                float  percent = 0;

                StreamWriter sw =  new  StreamWriter(path,  false ,Encoding.GetEncoding( "gb2312" ));
                StringBuilder sb =  new  StringBuilder();
                for  ( int  k = 0; k < ds.Tables[0].Columns.Count; k++)
                {
                    sb.Append(ds.Tables[0].Columns[k].ColumnName.ToString() +  "\t" );
                }
                sb.Append(Environment.NewLine);

                for  ( int  i = 0; i < ds.Tables[0].Rows.Count; i++)
                {
                    rowRead++;
                    percent = (( float )(100 * rowRead)) / totalCount;
                    Pbar.Maximum = ( int )totalCount;
                    Pbar.Value = ( int )rowRead;
                    lblTip.Text =  "正在写入["  + percent.ToString( "0.00" ) +  "%]...的数据" ;
                    System.Windows.Forms.Application.DoEvents();

                    for  ( int  j = 0; j < ds.Tables[0].Columns.Count; j++)
                    {
                        sb.Append(ds.Tables[0].Rows[i][j].ToString() +  "\t" );
                    }
                    sb.Append(Environment.NewLine);
                }
                sw.Write(sb.ToString());
                sw.Flush();
                sw.Close();
                MessageBox.Show( "已经生成指定Excel文件!" );
            }
            catch  (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

public  string  GetStrSql()
        {
            string  strSql =  "select d.* from ( select cBarcode ,max(case halldoorid  When '36' then '1' else '0' end ) [1.1号馆],max(case halldoorid  When '37' then '1' else '0' end ) [2.1号馆],max(case halldoorid  When '38' then '1' else '0' end ) [3.1号馆],max(case halldoorid  When '39' then '1' else '0' end ) [4.1号馆],max(case halldoorid  When '40' then '1' else '0' end ) [5.1号馆],max(case halldoorid  When '41' then '1' else '0' end ) [6.1号馆],max(case halldoorid When '42' then '1' else '0' end ) [8.1号馆],max(case halldoorid  When '43' then '1' else '0' end ) [1.2号馆],max(case halldoorid  When '44' then '1' else '0' end ) [2.2号馆],max(case halldoorid  When '45' then '1' else '0' end ) [3.2号馆],max(case halldoorid  When '46' then '1' else '0' end ) [4.2号馆],max(case halldoorid  When '47' then '1' else '0' end ) [5.2号馆],max(case halldoorid  When '48' then '1' else '0' end ) [9.1号馆],max(case halldoorid  When '49' then '1' else '0' end ) [10.1号馆],max(case halldoorid  When '50' then '1' else '0' end ) [11.1号馆],max(case halldoorid  When '51' then '1' else '0' end ) [12.1号馆],max(case halldoorid  When '52' then '1' else '0' end ) [13.1号馆],max(case halldoorid  When '53' then '1' else '0' end ) [9.2号馆],max(case halldoorid  When '54' then '1' else '0' end ) [10.2号馆],max(case halldoorid  When '55' then '1' else '0' end ) [11.2号馆],max(case halldoorid  When '56' then '1' else '0' end ) [12.2号馆],max(case halldoorid  When '57' then '1' else '0' end ) [13.2号馆],max(case halldoorid  When '58' then '1' else '0' end ) [9.3号馆],max(case halldoorid  When '59' then '1' else '0' end ) [10.3号馆],max(case halldoorid  When '60' then '1' else '0' end ) [11.3号馆],max(case halldoorid  When '61' then '1' else '0' end ) [VIP3.2号馆],max(case halldoorid  When '62' then '1' else '0' end ) [VIP11.3号馆],max(case halldoorid  When '63' then '1' else '0' end ) [VIP14.3号馆]from tblReadCard  group by cBarcode ) d left join ( select cBarcode 观众条码 from (select distinct cBarcode,cReadDate from tblReadCard where cReadDate between '2011-07-08' and '2011-07-11') a group by cBarcode  ) c on d.cBarcode=c.观众条码 group by cBarcode,[1.1号馆],[2.1号馆],[3.1号馆],[4.1号馆],[5.1号馆],[6.1号馆],[8.1号馆],[1.2号馆],[2.2号馆],[3.2号馆],[4.2号馆],[5.2号馆],[9.1号馆],[10.1号馆],[11.1号馆],[12.1号馆],[13.1号馆],[9.2号馆],[10.2号馆],[11.2号馆],[12.2号馆],[13.2号馆],[9.3号馆],[10.3号馆],[11.3号馆],[VIP3.2号馆],[VIP11.3号馆],[VIP14.3号馆]" ;
            return  strSql;
        }

---------------------------以下是用到自己项目中的代码片段--------------------------------------------
           string fileName= "XXXX导出"+DateTime.Now.ToString("yyyyMMddHHmmss")+".xls";//此时没有文件 后面会自动创建             string path = Server.MapPath("~/") + @"ExcelTemp\" + fileName;             string strResult = string.Empty;
               string strWhere = "XXXXXX";                 string orderby = "  XXXXX ";                 DataSet ds = bll.GetListOnExportExcel( strWhere, orderby);//此处获取DataSet(注意DataTable中的列名字就是表头，所以要提前在sql语句中写好中文列名)                 StreamWriter sw = new StreamWriter(path, false, Encoding.GetEncoding("gb2312"));                 StringBuilder sb = new StringBuilder();                 for (int k = 0; k < ds.Tables[0].Columns.Count; k++)                 {                     sb.Append(ds.Tables[0].Columns[k].ColumnName.ToString().Replace("\n", " ") + "\t");                 }                 sb.Append(Environment.NewLine);                 for (int i = 0; i < ds.Tables[0].Rows.Count; i++)                 {                     for (int j = 0; j < ds.Tables[0].Columns.Count; j++)                     {                         sb.Append(ds.Tables[0].Rows[i][j].ToString().Replace("\n", " ") + "\t");                     }                     sb.Append(Environment.NewLine);                 }                 sw.Write(sb.ToString());                 sw.Flush();                 sw.Close();                 //此时文件已经有了，传地址下载即可