IPostBackEventHandler question

[Henk]

Hey All,


I have a question about the IPostbackEventHandler interface. This
interface's RaisePostBackEvent method has an eventArgument paramter. When my
control has two buttons, I can use eventArgument to see what button was
clicked, since I set their onclick attribute with the
Page.ClientScript.GetPostBackEventReference(...) method.

When I then implement the IPostBackDataHandler interface, and call the
Page.RegisterRequireRaiseEvent, the RaisePostBackEvent still gets called
but the eventArgument parameter is always null? Why is this?

I know I can use the postCollection parameter in
IPostBackDataHandler::LoadPostData to check which button was clicked, but is
wonder why the IPostbackEventHandler::RaisePostBackEvent is not usable for
it anymore?


regards,

Henk

[Teemu Keiski]

It's implemented internally in Framework so that control getting registered
via RegisterRequiresRaiseEvent won't get the event argument (null is
passed). I suppose it is indeed presumed that it would be used in scenario
when the data is available with other means (postCollection in your case).
other is that Framework doesn't specifically keep track of the registered
control at that point (it hapåpens after postback data has been processed)


--
Teemu Keiski
ASP.NET MVP, AspInsider
Finland, EU
[url]http://blogs.aspadvice.com/joteke[/url]



"Henk" <SomeOne@the.Net> wrote in message
news:OYO1HbdBHHA.1220@TK2MSFTNGP04.phx.gbl...

> Hey All,
>
>
> I have a question about the IPostbackEventHandler interface. This
> interface's RaisePostBackEvent method has an eventArgument paramter. When
> my control has two buttons, I can use eventArgument to see what button was
> clicked, since I set their onclick attribute with the
> Page.ClientScript.GetPostBackEventReference(...) method.
>
> When I then implement the IPostBackDataHandler interface, and call the
> Page.RegisterRequireRaiseEvent, the RaisePostBackEvent still gets called
> but the eventArgument parameter is always null? Why is this?
>
> I know I can use the postCollection parameter in
> IPostBackDataHandler::LoadPostData to check which button was clicked, but
> is wonder why the IPostbackEventHandler::RaisePostBackEvent is not usable
> for it anymore?
>
>
> regards,
>
> Henk
>
>