FileUpload Control inside child UpdatePanel Not Working: FileUpload.Hasfile is always False

Question

I am using ajax toolkit PopupControl Extender to display row details of a gridview. The gridview is inside an Update panel. inside the popup window, there is a FileUpload control inside another UpdatePanel. In the child UpdatePanel where the FileUplad control sits, I set the trigger to a linkbutton which will upload file and update the database. My problem is the FileUpload.HasFile is alway false. How can I get it work?

The markup code is as follows:

    <asp:GridView ID="gdvTemplates" runat="server" AutoGenerateColumns="False" BorderWidth="0" GridLines="None">
    <Columns>
            .

. .

      <cc1:PopupControlExtender ID="Image1_PopupControlExtender" runat="server" 
                        DynamicServicePath="" Enabled="True" ExtenderControlID="" 
                        TargetControlID="Image1" PopupControlID="Panel1">
     </cc1:PopupControlExtender>

    <asp:Panel ID="Panel1" style="display:none" runat="server" CssClass="popup_template" Width="383px">

  <asp:FileUpload ID="FileUpload2" runat="server" />
  </td><td></td></tr> 

 <tr><td class="style7"></td><td class="style3">     

oncommand="LinkButton2_Click">Update Cancel

Some code is omitted. The question is how to get the FileUpload control work inside the child UpdatePanel in the Popup window.

Thanks.

Answer 1

This is because there MUST be a full postback for file upload, a partial post back will fail. Use IFrames for this, there are lots of examples of this.