Hi, I'm having issues displaying the photos in a gridview when exporting it to Excel. I have downloaded and followed this demo:

https://www.aspsnippets.com/Articles/Export-GridView-with-Images-to-Word-Excel-and-PDF-Formats-in-ASP.Net.aspx

The demo works fine on my computer but when I copied it over to my project, the photos aren't displayed in Excel at all, though they're shown on the gridview.

Here's my code:

<asp:GridView ID="gvResult" EnableViewState="true" RowStyle-Wrap="false" EmptyDataRowStyle-ForeColor="Red" EmptyDataRowStyle-BorderStyle="None" EmptyDataRowStyle-BorderColor="White" HeaderStyle-HorizontalAlign="Center" AutoGenerateColumns="false" CssClass="grid responsiveTable1" OnRowCommand="gvResult_RowCommand" runat="server" Width="900px"  DataKeyNames="ResultId" Style="margin-left: 0">
                <Columns>
                    <asp:TemplateField HeaderText="Name" SortExpression="Name">

                        <ItemTemplate>
                            <asp:Label ID="lblName" runat="server" Text='<%# Bind("Name") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>

                    <asp:TemplateField HeaderText="Username" SortExpression="Username" Visible="False">
                        <ItemTemplate>
                            <asp:Label ID="lblUsername" runat="server" Text='<%# Bind("Username") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>

                    <asp:TemplateField HeaderText="HRMS" SortExpression="HRMS">
                        <ItemTemplate>
                            <asp:Label ID="lblHRMS" runat="server" Text='<%# Bind("HRMS") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>

                    <asp:TemplateField HeaderText="Hub" SortExpression="Hub">
                        <ItemTemplate>
                            <asp:Label ID="lblHub" runat="server" Text='<%# Bind("Hub") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>

                    <asp:TemplateField Visible="false" InsertVisible="False" SortExpression="ResultId">

                        <ItemTemplate>
                            <asp:Label ID="lblResultId" runat="server" EnableViewState="true" Text='<%# Eval("ResultId") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="QuizId" Visible="false" SortExpression="QuizId">

                        <ItemTemplate>
                            <asp:Label ID="lblQuizId" runat="server" Text='<%# Bind("QuizId") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField DataField="QuizName" HeaderText="Quiz Name" SortExpression="QuizName" />
                    <asp:BoundField DataField="Mark" HeaderStyle-CssClass="hidden-xs" ItemStyle-CssClass="hidden-xs" HeaderText="Score" SortExpression="Mark" />
                    <asp:BoundField DataField="Result" Visible="false" HeaderText="Result" SortExpression="Result" />
                    <asp:BoundField DataField="TimeSubmitted" HeaderText="Time Submitted" HeaderStyle-CssClass="hidden-xs" ItemStyle-CssClass="hidden-xs" SortExpression="TimeSubmitted" />
                    <asp:BoundField DataField = "SignatureFileName" Visible="false" HeaderText = "Image Name" />
                    <asp:TemplateField ItemStyle-Height = "35" ItemStyle-Width = "100" HeaderText = "Signature">
                        <ItemTemplate>
                        <asp:Image ID="Image1" Width="100px" Height="35px"  runat="server" ImageUrl = '<%# Eval("ResultId", GetUrl("ImageSignature.aspx?SignatureId={0}"))%>' />
                        </ItemTemplate> 
                     </asp:TemplateField>
                     <%--<asp:ImageField AlternateText="No signature found." DataImageUrlField="ResultId" DataImageUrlFormatString="ImageSignature.aspx?SignatureId={0}"
                        ControlStyle-Width="50%" ControlStyle-Height="50%" ControlStyle-CssClass="text-center" HeaderText="Signature" />--%>
                    <asp:CommandField ShowSelectButton="True" SelectText="View Details" />
                </Columns>

                <HeaderStyle HorizontalAlign="Center"></HeaderStyle>

            </asp:GridView>

Code behind:

protected void btnExcel_Click(object sender, EventArgs e)
        {
            if (gvResult.Rows.Count > 0)
            {
                btnExcel.Visible = true;
                btnExcel.BackColor = System.Drawing.ColorTranslator.FromHtml("#5bc0de");
                Response.Clear();
                Response.Buffer = true;
                Response.AddHeader("content-disposition",
                 "attachment;filename=QuizResults.xls");
                Response.Charset = "";
                Response.ContentType = "application/vnd.ms-excel";

                Response.ContentEncoding = System.Text.Encoding.Unicode;
                Response.BinaryWrite(System.Text.Encoding.Unicode.GetPreamble());

                StringWriter sw = new StringWriter();
                HtmlTextWriter hw = new HtmlTextWriter(sw);
                for (int i = 0; i < gvResult.Rows.Count; i++)
                {
                    GridViewRow row = gvResult.Rows[i];
                    //Apply text style to each Row
                    row.Attributes.Add("class", "textmode");
                }
                gvResult.RenderControl(hw);

                //style to format numbers to string
                string style = @"<style> .textmode { mso-number-format:\@; } </style>";
                Response.Write(style);
                Response.Output.Write(sw.ToString());
                Response.Flush();
                Response.End();
            }
        }
        protected string GetUrl(string page)
        {
            string[] splits = Request.Url.AbsoluteUri.Split('/');
            if (splits.Length >= 2)
            {
                string url = splits[0] + "//";
                for (int i = 2; i < splits.Length - 1; i++)
                {
                    url += splits[i];
                    url += "/";
                }
                return url + page;
            }
            return page;
        }

Could anyone please help take a look to see what I need to fix? Thanks!