Uploading Image to Sql Server Image Datatype in asp.net using fileupload Control

Asp.net c# code to Render Gridview Control

  public override void VerifyRenderingInServerForm(Control control)
    {
        /* Verifies that the control is rendered */
    }

protected void BtnPayment_Click(object sender, EventArgs e)
    {
 using (StringWriter sw = new StringWriter())
            {
                using (HtmlTextWriter hw = new HtmlTextWriter(sw))
                {
                    GridViewCart.RenderControl(hw);
                    StringReader sr = new StringReader(sw.ToString());
                    string tablehtml = "GridView:<hr />" + sw.ToString();
                }
            }
}