Hi,

I have a LinkButton within update panel and on button click i want to download xlsx file from server.

But due to update panel file download is not happening.

This is my code.

protected void LinkButton2_Click(object sender, EventArgs e)
{
    LinkButton btn = (LinkButton)(sender);
    string yourValue = btn.CommandArgument;
    string[] ar = btn.CommandArgument.ToString().Split('|');
 
    MTemptyxlxs();
 
    DataSet ds = new DataSet();
 
    using (MySqlConnection con =
      new MySqlConnection(ConfigurationManager.ConnectionStrings["cn"].ConnectionString))
    {
        using (MySqlCommand cmd =
            new MySqlCommand("sp_gv", con))
        {
            cmd.CommandTimeout = 2147483;
            cmd.Connection.Open();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.Clear();
 
            cmd.Parameters.AddWithValue("@spAAA", ar[0].ToString());
            cmd.Parameters.AddWithValue("@spBBB", ar[1].ToString());
            cmd.Parameters.AddWithValue("@spCCC", ar[2].ToString());
 
            MySqlDataAdapter da = new MySqlDataAdapter(cmd);
            da.Fill(ds);
            ExportDataSetToExcel(ds);
        }
    }
}
 
public static void ExportDataSetToExcel(DataSet ds)
{
    string AppLocation = @"D:\inetpub\wwwroot\aspnet\";
    string guid = Guid.NewGuid().ToString().ToUpper().Replace("-", "_");
 
    HttpContext.Current.Response.Cookies["guid"].Value = guid.ToString();
    HttpContext.Current.Response.Cookies["guid"].Expires = DateTime.Now.AddMinutes(3);
 
    string filepath = AppLocation + "Export_" +
        DateTime.Now.ToString("ddMMyyyyHHmm") + "_" +
        HttpContext.Current.Response.Cookies["guid"].Value + ".xlsx";
 
    using (XLWorkbook wb = new XLWorkbook())
    {
        for (int i = 0; i < ds.Tables.Count; i++)
        {
            wb.Worksheets.Add(ds.Tables[i], ds.Tables[i].TableName);
        }
        wb.Style.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
        wb.Style.Font.Bold = true;
        wb.SaveAs(filepath);
        wb.Dispose();
    }
 
    Thread.Sleep(3000);
    HttpContext.Current.Response.Clear();
    HttpContext.Current.Response.Buffer = true;
    HttpContext.Current.Response.ContentType = "application/force-download";
 
    HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment; filename=Export_" +
        DateTime.Now.ToString("ddMMyyyyHHmm") + "_" +
        HttpContext.Current.Response.Cookies["guid"].Value + ".xlsx");
 
    HttpContext.Current.Response.TransmitFile(@"D:\inetpub\wwwroot\aspnet\Export_" +
        DateTime.Now.ToString("ddMMyyyyHHmm") + "_" +
        HttpContext.Current.Response.Cookies["guid"].Value + ".xlsx");
 
    HttpCookie cookie = new HttpCookie("ExcelDownloadFlag")
    {
        Value = "Flag",
        Expires = DateTime.Now.AddDays(1)
    };
 
    HttpContext.Current.Response.AppendCookie(cookie);
    HttpContext.Current.Response.End();
}

<asp:TemplateField
    ItemStyle-HorizontalAlign="Center"
    ItemStyle-CssClass="ddl_Class_new"
    HeaderText="Nr.">
    <ItemTemplate>
        <asp:UpdateProgress ID="UpdateProgress1" runat="server"
            AssociatedUpdatePanelID="UpdatePanel1">
            <ProgressTemplate>
                <div class="modal">
                    <div class="center">
                        <img alt="" src="/aspnet/img/ajax-loader.gif" />
                    </div>
                </div>
            </ProgressTemplate>
        </asp:UpdateProgress>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
            <Triggers>
                <asp:AsyncPostBackTrigger ControlID="LinkButton2" />
            </Triggers>
            <ContentTemplate>
                <asp:LinkButton ID="LinkButton2" runat="server"
                    CssClass="ddl_Class_new"
                    OnClick="LinkButton2_Click"
                    CommandArgument='<%# Eval("AAA") + "|" + Eval("BBB") + "|" + Eval("CCC") %>'
                    Text='<%# Eval("Cr") %>'></asp:LinkButton>
            </ContentTemplate>
        </asp:UpdatePanel>
    </ItemTemplate>
</asp:TemplateField>