Gradview绑定数据库数据并导出Excel

Code
protected void showData_Click(object sender, EventArgs e)
{
SqlConnection myConnection
= new SqlConnection("Data Source=localhost;Initial Catalog=test;User ID=sa;password=sa");

SqlDataAdapter ad = new SqlDataAdapter("SELECT * FROM booklist", myConnection);
DataSet ds = new DataSet();
ad.Fill(ds);
this.gvShowData.DataSource = ds;
this.gvShowData.DataBind();
}

//导出Excel表
protected void btnExportToExcel_Click(object sender, EventArgs e)
{
Response.Charset = "GB2312";
Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
Response.AddHeader("Content-Type", "application/vnd.ms-excel");
Response.AddHeader("Content-Disposition", "myexcelfile.xls");
//以此编码模式导出才不会出现乱码
StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
gvShowData.RenderControl(htw);
Response.Write(sw.ToString());
Response.End();
}

//一定要写，否则出错！！
public override void VerifyRenderingInServerForm(Control control)
{
}