Problem with 'CommandBinding' and 'PreviewExecuted'

Hi,

Has anybody encountered a problem such as this one:

In a Window, I declare a command binding to the 'copy' command... In
the command binding declaration, I map a function to the
'PreviewExecuted' routed event and to the 'Executed' routed event.

The XAML looks as follows:

<Window.CommandBindings>
<CommandBinding
Command="ApplicationCommands.Copy"
Executed="HandlerCopyExecute"
PreviewExecuted="HandlerCopyPreviewExecute"
/>
</Window.CommandBindings>

My problem is that whenever I map an Handler to the "PreviewExecuted"
event, then I won't receive the "Executed" event....

If I remove the handler to the "PreviewExecuted" event, then the
"Executed" event is called.

I did not find any indication in the SDK documentation indicating that
a particular action is required in the "PreviewExecuted" handler in
order to allow the "Executed" to occur!

I am using the February CTP, and I'm starting to wonder if this is a
bug in the WPF

Thanks

It seems that Microsoft deliberately prevents us from having PreviewExecuted
and Exectued events fired simultaneously, here is the evidence:
internal void OnExecuted(object sender, ExecutedRoutedEventArgs e)
{
if (!e.Handled)
{
if (e.RoutedEvent == CommandManager.ExecutedEvent)
{
if ((this.Executed == null) ||
!this.CheckCanExecute(sender, e))
{
return;
}
this.Executed(sender, e);
e.Handled = true;
}
else if ((this.PreviewExecuted != null) &&
this.CheckCanExecute(sender, e))
{
this.PreviewExecuted(sender, e);
e.Handled = true;
}
}
}
This method is a part of implementation of CommandBinding class.Sheva

"Marcus" <larochem@gmail.com> wrote in message
news:1141392914.254252.14250@i39g2000cwa.googlegroups.com...
> Hi,
>
> Has anybody encountered a problem such as this one:
>
> In a Window, I declare a command binding to the 'copy' command... In
> the command binding declaration, I map a function to the
> 'PreviewExecuted' routed event and to the 'Executed' routed event.
>
> The XAML looks as follows:
>
> <Window.CommandBindings>
> <CommandBinding
> Command="ApplicationCommands.Copy"
> Executed="HandlerCopyExecute"
> PreviewExecuted="HandlerCopyPreviewExecute"
> />
> </Window.CommandBindings>
>
> My problem is that whenever I map an Handler to the "PreviewExecuted"
> event, then I won't receive the "Executed" event....
>
> If I remove the handler to the "PreviewExecuted" event, then the
> "Executed" event is called.
>
> I did not find any indication in the SDK documentation indicating that
> a particular action is required in the "PreviewExecuted" handler in
> order to allow the "Executed" to occur!
>
> I am using the February CTP, and I'm starting to wonder if this is a
> bug in the WPF
>
> Thanks
>

After this answer from Sheva, I took a deeper look at the code and
realized the following...

The "PreviewExecuted" in the CommandBinding is completelly useless...

>From what I see, the CommandBinding object only registers to the
"Executed" RoutedEvent of the Command... Meaning that the "tunneling"
effect expected from the "PreviewExecuted" would not occur, it is
simply the same thing as the the "Executed"...

Why would Microsoft put a "Preview" executed in the CommandBinding
then?

More than that, even if it can be "easilly" deduced, the events
originating from the "CommandBinding" are not routed at all, they are
plain old .NET events... I originally had some confusion about routing
of the command events because of it...

The code snippet from Sheva illustrate that behavior really well...

Thanks a lot...


Sheva wrote:
> It seems that Microsoft deliberately prevents us from having PreviewExecuted
> and Exectued events fired simultaneously, here is the evidence:
> internal void OnExecuted(object sender, ExecutedRoutedEventArgs e)
> {
> if (!e.Handled)
> {
> if (e.RoutedEvent == CommandManager.ExecutedEvent)
> {
> if ((this.Executed == null) ||
> !this.CheckCanExecute(sender, e))
> {
> return;
> }
> this.Executed(sender, e);
> e.Handled = true;
> }
> else if ((this.PreviewExecuted != null) &&
> this.CheckCanExecute(sender, e))
> {
> this.PreviewExecuted(sender, e);
> e.Handled = true;
> }
> }
> }
> This method is a part of implementation of CommandBinding class.Sheva
>
> "Marcus" <larochem@gmail.com> wrote in message
> news:1141392914.254252.14250@i39g2000cwa.googlegroups.com...
> > Hi,
> >
> > Has anybody encountered a problem such as this one:
> >
> > In a Window, I declare a command binding to the 'copy' command... In
> > the command binding declaration, I map a function to the
> > 'PreviewExecuted' routed event and to the 'Executed' routed event.
> >
> > The XAML looks as follows:
> >
> > <Window.CommandBindings>
> > <CommandBinding
> > Command="ApplicationCommands.Copy"
> > Executed="HandlerCopyExecute"
> > PreviewExecuted="HandlerCopyPreviewExecute"
> > />
> > </Window.CommandBindings>
> >
> > My problem is that whenever I map an Handler to the "PreviewExecuted"
> > event, then I won't receive the "Executed" event....
> >
> > If I remove the handler to the "PreviewExecuted" event, then the
> > "Executed" event is called.
> >
> > I did not find any indication in the SDK documentation indicating that
> > a particular action is required in the "PreviewExecuted" handler in
> > order to allow the "Executed" to occur!
> >
> > I am using the February CTP, and I'm starting to wonder if this is a
> > bug in the WPF
> >
> > Thanks
> >