🚀 go-pugleaf

"Lapo" <lapoguidi@inwind.it> wrote in message
news:3ed00a13@newsgroups.borland.com...

> I see that every time the TImage is updated using
> Synchronize, as a said before, the Thread seems
> freezed until the updating is done.

Correct.  That is intentional by design.  Synchronize() blocks the calling
thread until the callback method pased to it is actually executed.  This
prevents multiple synchronized threads from executing at the same time, such
as in scenerios when they are sharing and accessing the same protected
resource(s).

> Well, I read something about PostMessage/SendMessage
> to communicate from Thread to Main Application

That is a possibility.  However, keep in mind that SendMessage() will also
block the calling thread until the message is actually processed (in fact,
up to and including BCB5, Synchronize() uses SendMessage() internally).

> so the thread can ask the main application to update the
> TImage and it doesn't wait for the updating is over.

That is possible.  PostMessage() would be well suited for that.  However,
the actual image data will have to be stored somewhere in memory where the
main application thread can get to it, and you will have to ensure that you
are not modifying the data from your thread at the same time that the main
thread is accessing it for display, and that the data is still valid in
memory by the time the message is eventually processed.  PostMessage()
returns immediately, the message queued for later processing when the
receiving thread eventually removes the message from its message queue.


Gambit