asp.net 将GridView中的数据导出到Excel

protected void Page_Load(object sender, EventArgs e)
{
VerifyRenderingInServerForm(gv1);
bindgv();
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Clear();
Response.AddHeader("content-disposition", "attachment;filename=FileName.xls");
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.Default;

Response.Charset = "GB2312"; ;
Response.ContentType = "application/vnd.ms-excel;charset=GB2312";
System.IO.StringWriter stringWrite = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
gv1.RenderControl(htmlWrite);
Response.Write(stringWrite.ToString());
Response.End();

}
protected void bindgv()
{
string connstr = "server=.;database=netchucai;uid=sa;pwd=david5188";
SqlConnection conn = new SqlConnection(connstr);
conn.Open(); //打开数据库
string sqlstr = "select * from daoru";
SqlDataAdapter sda = new SqlDataAdapter(sqlstr, conn);
DataSet ds = new DataSet();
sda.Fill(ds, "daoru");
gv1.DataSource=ds.Tables["daoru"];
gv1.DataBind();
}
public override void VerifyRenderingInServerForm(Control control)
{
// Confirms that an HtmlForm control is rendered for
}