🚀 go-pugleaf

"Jeff Douglass" <.> wrote in message news:3ea817c4@newsgroups.borland.com...
> If I use the actual handle of the startup window in the call
> to PostMessage() everything works fine but when I try using
> the HWND_BROADCAST constant it does not work. Any
> ideas would be great.

What does your actual code look like?  What kind of message are you trying
to broadcast specifically?  Some messages can't be broadcasted with
PostMessage(), they need SendMessage() instead.

Is there any reason why you're broadcasting in the first place instead of
simply looking for the startup window specifically?


Gambit

I am trying to use the broadcast option so in case at a later point in time
I need to perform some added processing from any number of different windows
the hook is already there.

The message is simply defined as
#define THE_MESSAGE (WM_USER + 3332)

At the end of the initializtion routine that handles all the app's
initialization I call:

PostMessage(HWND_BROADCAST, THE_MESSAGE,0,0);

The startup window is created and shown as follows:

Application->Initialize() ;
startupwindow->Show();
startupwindow->Update();

the call to the app's initialization routine.


The only thing I can think is the problem is that the startup window is not
a "top level window" The MS documentation of PostMessage says that the
broadcast option send the message to all "top level windows" but not child
windows. I can not find an exact definition of what makes a window a "top
level window". My app is a SDI app so there are no child windows.

Hope this info helps answer the problem.

Thanks again

Jeff

"Jeff Douglass" <.> wrote in message
news:3ea8274c$1@newsgroups.borland.com...

> The message is simply defined as
> #define THE_MESSAGE (WM_USER + 3332)

I would suggest you consider having a look at the RegisterWindowMessage()
function.  The one gotcha with hard-coded message IDs is that you never know
when someone else is using the same ID for their own stuff.  Especially in a
scenerio where you're broadcasting the message to everyone.  Using
RegisterWindowMessage() ensures you have a unique value that only you know
how to interpret (and anyone else specifically written to directly support
your message).

> The only thing I can think is the problem is that the startup
> window is not a "top level window"

Very possibly.  VCL forms are not stand-alone.  They are actually children
of the hidden global TApplication window, which is the true top-level window
for the program.  You will probably need to assign an event handler to the
TApplication::OnMessage event in order to intercept your broadcast
correctly.  Otherwise, you'll have to override the form's CreateParams()
method to reassign the owner window (in API terms, not VCL) to be the main
Desktop window instead.  That might have other side-effects on how the VCL
form behaves, though.


Gambit

Thanks for advice. BTW, could you take a look at my posting "ClientSocket
Problem" in the sockets group. You seem to always have all the answers and
no one has posted any responses to it. Thanks again.


Jeff