java转型自学.NET 怎么在后台控制imge控件

java转型自学.NET 如何在后台控制imge控件啊
这个事后台
 DataTable dt = new SysAppClassBLL().GetBugClass(wtfl, wtms, flmx, wtpt);
            this.rptList.DataSource = dt;
            this.rptList.DataBind();
            if (dt.Rows.Count > 0) {
                for (int i = 0; i < dt.Rows.Count;i++ )
                {
                    DateTime nowdtae = System.DateTime.Now.Date;
                    DateTime indate = Convert.ToDateTime(dt.Rows[i]["InDate"]);
                    TimeSpan ts = (TimeSpan)Convert.ToDateTime(nowdtae).Subtract(Convert.ToDateTime(indate));
                    if (ts.Days <= 3) {
                        foreach (RepeaterItem item in rptList.Items)
                        {
                            string divname = "imgediv “+i;
                            HtmlGenericControl div1 = item.FindControl(divname) as HtmlGenericControl;
                           div1.Style["Display"] = "Block";
                         }
                    }
                    
                }
            }
            RecordCount = dt.Rows.Count;

这个事前端：
<tbody class="list-con">
            <asp:Repeater ID="rptList" runat="server">
                <ItemTemplate>
                    <tr class="list-bd">
                        <td style="text-align:left;">
                            <div id="imgediv<%#Eval("id")%>" runat="server" style="display: none">
                                <asp:Image ID="Image1" runat="server" ImageUrl="~/img/new11.gif" />
                            </div>
                            <a href="faqdaan.aspx?id=<%#Eval("id")%>&gjz=<%=wtms%>&pt=<%=wtpt%>&lx=<%=flmx%>&fl=<%=wtfl%>"><%#Eval("Question") %></a>
                        </td>
                        <td><%#Eval("Platform") %></td>
                        <td><%#Eval("QuestionType") %></td>
                        <td>
                            <a href="faqdaan.aspx?id=<%#Eval("id")%>&gjz="111"&pt=<%=wtpt%>&lx=<%=flmx%>&fl=<%=wtfl%>">详细</a>