c# 大批量数据导出到excel[1]

 c# 大批量数据导出到excel[此为个人分享]

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,或者看看我另外一篇日志：c# 大批量数据导出到excel[2]】
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！]

需要引用：
using System.Threading;
using System.IO;
方法如下：
 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;
   }

转自 http://csharp123.blog.163.com/blog/static/184371081201162413440681/