Re: Consuming your own events.

Well, I understand your scenario better now, but ... this is (up to
now) specific to WPF and it is not the first time that the one making
guidelines is breaking them .... *cough* binding *cough*.

Why would this apply to, say, ObservableCollection<T> ?

Sébastien

On 1/30/08, Sebastien Lambla <[email protected]> wrote:
> I'm talking about using attached events that your type is not an owner of.
> For example
>
> public event MouseButtonEventHandler MouseDown
> {
>     add
>     {
>         this.AddHandler(Mouse.MouseDownEvent, value, false);
>     }
>     remove
>     {
>         this.RemoveHandler(Mouse.MouseDownEvent, value);
>     }
> }
>
>
> Now let's see what the OnMouseDown method is.
>
> protected virtual void OnMouseDown(MouseButtonEventArgs e)
> {
> }
>
> Sparing you with the nasty details:
> EventManager.RegisterClassHandler(typeof(UIElement), Mouse.MouseDownEvent,
> new MouseButtonEventHandler(UIElement.OnMouseDownThunk), true);
>
>
> So the next generation UI framework uses OnXxx for event handling (not
> raising!). Raising itself uses the RaiseEvent method.
>
> This conflicts with the guidelines that have been discussed, conflict less
> with the ones i've just explained. Because of that, I advise against using
> the On notation, to prevent the confusion introduced by different
> frameworks...
>
> --
> SerialSeb
> http://serialseb.blogspot.com
>
>
> > -----Original Message-----
> > From: Discussion of development on the .NET platform using any managed
> > language [mailto:[email protected]] On Behalf Of Sébastien
> > Lorion
> > Sent: 30 January 2008 11:45
> > To: [email protected]
> > Subject: Re: [DOTNET-CLR] Consuming your own events.
> >
> > On 1/30/08, Sebastien Lambla <[email protected]> wrote:
> > >
> > > When you start, like in WPF, using different property stores for your
> > > events, the problem becomes even worse (and it's that problem that
> > has
> > > triggered my move to this new pattern).
> >
> >
> > Could you elaborate on this bit, I am not sure I follow you. I think
> > you mean to use a hashtable to associate events to their delegate
> > instead of default
> > storage (ie one field by event) ? If so, how is it affected by the
> > OnXXX pattern ?
> >
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-- 
Sébastien
www.sebastienlorion.com

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