我的页面上有一个GridView
和一个按钮,点击按钮后怎么刷新GridView//绑定代码
private void FillGrid()
{
   //........
   this.GridView1.DataSource = ds.Tables[0];
   this.GridView1.DataBind();
}//下载代码
public void ExportDate(string FileType ,string strContent,string ExpID,string FileName)
    {
        Response.Clear();
        Response.Charset = "gb2312";
        Response.ContentEncoding = Encoding.GetEncoding("gb2312");
        Response.HeaderEncoding = Encoding.GetEncoding("gb2312");
        Response.ContentType = FileType;//image/JPEG;text/HTML;image/GIF;wnd.ms-excel/msword; application/ms-excel
        Response.AppendHeader("Content-Disposition", "attachment;filename="+FileName);
        Response.Write(strContent.ToString());
        Response.End();
    } //点击按钮
private void btnDownLoad_Click(object sender,EventArgs e)
{
   ExportDate(参数略);
   FillGridView();
}这样更新不了,怎么解决?谢谢,分不多