原文发布时间为：2008-10-11 —— 来源于本人的百度文章 [由搬家工具导入]

这个例子是从gridview中导出到Excel，可以举一反三，可以直接从数据库中取值放在DataSet中，然后再从DataSet中导出到Excel，原理是一样的。。。。

例子：

网站文件夹中的所有内容：

excel中的内容：[具有固定的Excel表头]

后台代码：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.IO;
using System.Data.OleDb;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string NewFileName = DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls";
        NewFileName = Server.MapPath(NewFileName) ;
        //根据模板正式生成该Excel文件
        File.Copy(Server.MapPath("~/Module01.xls"), NewFileName,true);
        //建立指向该Excel文件的数据库连接
        string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + NewFileName + ";Extended Properties='Excel 8.0;'";
        OleDbConnection Conn = new OleDbConnection(strConn);
        Conn.Open();
        OleDbCommand Cmd = new OleDbCommand("", Conn);
        foreach (GridViewRow gr in GridView1.Rows)
        {
            string sql = "insert into [Sheet1$]";
            sql += "([课程编号],[课程名字]) values(";
            sql += "'" + gr.Cells[0].Text + "','" + gr.Cells[1].Text + "')";
            Cmd.CommandText = sql;
            Cmd.ExecuteNonQuery();
        }
        Conn.Close();
        //打开要下载的文件，并把该文件存放在FileStream中
        FileStream fs = File.OpenRead(NewFileName);
        //文件传送的剩余字节数：初始值为文件的总大小
        long length = fs.Length;

        Response.Buffer = false;
        Response.AddHeader("Connection", "Keep-Alive");
        Response.ContentType = "application/octet-stream";
        Response.AddHeader("Content-Disposition", "attachment;filename=" + Server.UrlEncode("课程.xls"));
        Response.AddHeader("Content-Length", length.ToString());

        //存放欲发送数据的缓冲区
        byte[] buf = new byte[1000];

        //每次实际读取的字节数
        int ByteToRead;
        //剩余字节数不为零，继续传送
        while (length > 0)
        {
            //客户端浏览器还打开着，继续传送
            if (Response.IsClientConnected)
            {
                //往缓冲区读入数据
                ByteToRead = fs.Read(buf, 0, 1000);
                //把缓冲区的数据写入客户端浏览器
                Response.OutputStream.Write(buf, 0, ByteToRead);
                //立即写入客户端
                Response.Flush();
                //剩余字节数减少
                length -= ByteToRead;
            }
            else
            {
                //客户端浏览器已经断开，阻止继续循环
                length = -1;
            }
        }
        fs.Close();
        File.Delete(NewFileName);
    }
}

第二种方法：

protected void Button2_Click(object sender, EventArgs e)
    {
        Response.Clear();
        Response.Buffer = true;    
        Response.AddHeader("Content-Disposition", "attachment;filename=" + Server.UrlEncode("课程.xls")); //定义输出文件和文件名
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文
        Response.ContentType = "Excel";//设置输出文件类型为excel文件。
        this.EnableViewState =false;
        System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("ZH-CN", true);
        StringWriter oStringWriter = new StringWriter(myCItrad);
        HtmlTextWriter oHtmlTextWriter = new HtmlTextWriter(oStringWriter);
        this.GridView1.RenderControl(oHtmlTextWriter); //要导出的DataGrid
        Response.Write(oStringWriter.ToString());
        Response.End();
    }
    //上面的方法 还要在这个页面中重载这个方法 不然会出以下的异常
    // 类型“GridView”的控件“GridView1”必须放在具有 runat=server 的窗体标记内。
    public override void VerifyRenderingInServerForm(Control control)
    {
    }

从数据库的表导出到Excel表格中【让客户端下载的Excel】