如何将数据绑到gridview然后导成excel

using system;
using system.collections.generic;
using system.linq;
using system.web;
using system.web.ui;
using system.web.ui.webcontrols;
using system.data .sqlclient ;
using system.data ;

public partial class _default : system.web.ui.page
{
protected void page_load(object sender, eventargs e)
{
string sqlconn = "server=.; database=db; integrated security=sspi ";
string sql = "select top 10 * from table";

sqlconnection myconnection = new sqlconnection(sqlconn);// 创建数据库连接实例

myconnection.open(); //打开数据库

sqlcommand mycommand = new sqlcommand(sql, myconnection);//创建sql的实例，执行一个sql


sqldataadapter adapter = new sqldataadapter();//创建一个sql数据适配器
adapter.selectcommand = mycommand;//属性设置为 从数据源中检索记录


dataset myds = new dataset(); //创建数据集实例
adapter.fill(myds);//填充数据集

gridview1.datasource = myds.tables[0].defaultview;//
gridview1.databind();

// datatoexcel("测试的cxcel", gridview1);
myconnection.close();//关闭数据库连接
}
public void datatoexcel(string filename, gridview mygridview)
{
//定义文档类型、字符编码
response.clear();
response.buffer = false;
//response.charset = "utf-8";
response.charset = "gb2312";
//下面这行很重要， attachment 参数表示作为附件下载，您可以改成 online在线打开
//filename=fileflow.xls 指定输出文件的名称，注意其扩展名和指定文件类型相符，可以为：.doc || .xls || .txt ||.htm
response.appendheader("content-disposition", "attachment;filename=" + system.web.httputility.urlencode(filename, system.text.encoding.utf8) + ".xls");
response.contentencoding = system.text.encoding.getencoding("utf-8");
//response.contentencoding = system.text.encoding.getencoding("gb2312");
//response.contenttype指定文件类型 可以为application/ms-excel || application/ms-word || application/ms-txt || application/ms-html || 或其他浏览器可直接支持文档
response.contenttype = "application/ms-excel";
this.enableviewstate = false;
//system.globalization.cultureinfo mycitrad = new system.globalization.cultureinfo("zh-cn", true);
//定义一个输入流
system.io.stringwriter ostringwriter = new system.io.stringwriter();
system.web.ui.htmltextwriter ohtmltextwriter = new system.web.ui.htmltextwriter(ostringwriter);
//将目标数据绑定到输入流输出
mygridview.rendercontrol(ohtmltextwriter);
response.write(ostringwriter.tostring());
response.end();
}

//下面这个空语句一定要加，否则会出现“必须放在具有 runat=server 的窗体标记内。”的错误
public override void verifyrenderinginserverform(control control)
{
}

//点击事件，生成excel
protected void button1_click(object sender, eventargs e)
{
datatoexcel("测试的cxcel", gridview1);
}
}