ASP.Net Error: System.Web.UI.WebControls.Panel does not contain definition for DrawToBitmap

Hi dd50957,

Please refer below sample.

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript" src="https://github.com/niklasvh/html2canvas/releases/download/v1.0.0-alpha.8/html2canvas.min.js"></script>
<script type="text/javascript">
    function ConvertToImage(btnExport) {
        html2canvas($("#pnlContent")[0]).then(function (canvas) {
            var base64 = canvas.toDataURL();
            $("[id*=hfImageData]").val(base64);
            __doPostBack(btnExport.name, "");
        });
        return false;
    }
</script>
<div>
    <asp:Panel runat="server" ID="pnlContent" Style="width: 340px; background-color: White;
        padding: 5px">
        <table cellspacing="0" rules="all" border="1" style="border-collapse: collapse;">
            <tr>
                <th scope="col" style="width: 90px;">Customer Id</th>
                <th scope="col" style="width: 120px;">Name</th>
                <th scope="col" style="width: 120px;">Country</th>
            </tr>
            <tr>
                <td>1</td>
                <td>John Hammond</td>
                <td>United States</td>
            </tr>
            <tr>
                <td>2</td>
                <td>Mudassar Khan</td>
                <td>India</td>
            </tr>
            <tr>
                <td>3</td>
                <td>Suzanne Mathews</td>
                <td>France</td>
            </tr>
            <tr>
                <td>4</td>
                <td>Robert Schidner</td>
                <td>Russia</td>
            </tr>
        </table>
    </asp:Panel>
    <br />
    <asp:HiddenField ID="hfImageData" runat="server" />
    <asp:Button ID="btnExport" Text="Export to Image" runat="server" UseSubmitBehavior="false"
        OnClick="ExportToImage" OnClientClick="return ConvertToImage(this)" />
</div>

Code

C#

protected void ExportToImage(object sender, EventArgs e)
{
    string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];
    byte[] bytes = Convert.FromBase64String(base64);

    Response.Clear();
    Response.ContentType = "image/png";
    Response.AddHeader("Content-Disposition", "attachment; filename=HTML.jpeg");
    Response.Buffer = true;
    Response.Cache.SetCacheability(HttpCacheability.NoCache);
    Response.BinaryWrite(bytes);
    Response.End();
}

VB.Net

Protected Sub ExportToImage(sender As Object, e As EventArgs)
    Dim base64 As String = Request.Form(hfImageData.UniqueID).Split(",")(1)
    Dim bytes As Byte() = Convert.FromBase64String(base64)
    Response.Clear()
    Response.ContentType = "image/png"
    Response.AddHeader("Content-Disposition", "attachment; filename=HTML.jpeg")
    Response.Buffer = True
    Response.Cache.SetCacheability(HttpCacheability.NoCache)
    Response.BinaryWrite(bytes)
    Response.End()
End Sub