The pdf exporter does not export images and also table background color. In the aspx pages the table has background color but the exported pdf file, the table comes out blank without background color, but the grid view still retains its color.

My code

public partial class pdf : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            DataTable dt = new DataTable();
            dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id"), new DataColumn("Name"), new DataColumn("Country") });
            dt.Rows.Add(1, "John Hammond", "United States");
            dt.Rows.Add(2, "Mudassar Khan", "India");
            dt.Rows.Add(3, "Suzanne Mathews", "France");
            dt.Rows.Add(4, "Robert Schidner", "Russia");
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }
    }

    protected void ExportToPDF(object sender, EventArgs e)
    {
        using (StringWriter sw = new StringWriter())
        {
            using (HtmlTextWriter hw = new HtmlTextWriter(sw))
            {
                Panel1.RenderControl(hw);
             
                StringReader sr = new StringReader(sw.ToString());
                Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
                PdfWriter writer = PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
                pdfDoc.Open();
                XMLWorkerHelper.GetInstance().ParseXHtml(writer, pdfDoc, sr);
                pdfDoc.Close();
                Response.ContentType = "application/pdf";
                Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.pdf");
                Response.Cache.SetCacheability(HttpCacheability.NoCache);
                Response.Write(pdfDoc);
                Response.End();
            }
        }
    }

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

please help