Howto write a client-side component that can do callbacks ?

Hi,


I would like to write a component that can do callbacks to send asynchronously data to server.
Here, the goal is to upload binary data from an activex or a java applet to the server and let the Webcontrol raise a "IncomingData" event.
The only part that is missing for me is how to easily do the callback, using the AjaxControlToolkit design patterns (inheriting from AjaxControlToolkit.ScriptControlBase).


Does the ExtenderControlMethodAttribute can be the solution ?


Thanks.

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