Ajax Content Loading(Processing) image or indicator

in part of my web page, I have couple of asp:image Thumbnails, onclick I use ajax modal popup extender to show the imgae in full size which are working fine, what I need to add is to have a processing image or indicator both in thumbnail and modal popup extender,

I also have ajax autocomplete that is working fine, I need to add so开发者_如何学Cme indicator or processing image to it as soon as user start typing a word.

any idea?

Thanks in advance

You can use an update progress control to display a progress template within your update panel. It displays the contents of the ProgressTemplate tag whenever a postback occurs:

<asp:UpdateProgress runat="server" id="UpdateProgress" AssociatedUpdatePanelID="SomePanel" >
    <ProgressTemplate>
        <img src="processing.gif" alt="Processing" />
    </ProgressTemplate>
</asp:UpdateProgress>

Also, I've found Preloaders useful as a source of animated GIFs for this purpose.

Look at http://www.ajaxload.info/. There are a ton of images there. Once the user types in some letters, however many you need, then display the ajax loader gif next to the textbox.

Assuming that you want the loader/indicator within control, so, one way could be to subclass the PopupExtender control, add asp:UpdateProgress, and put a loader.img in there.