🚀 go-pugleaf

It is hard to diagnose your problem without seeing yuor actual code.  But
offhand, it sounds like you are trying to draw directly onto the PaintBox
from your thread directly.  If so, then you shouldn't be doing that, as the
VCL is not thread-safe and can't handle cross-thread painting correctly.
Instead, you should be doing your thread-based drawing to a separate
in-memory bitmap that is properly protected by a synchronization object
(mutex, critical section, semaphore, etc), and then the thread can obtain
the lock to the bitmap when it needs to alter the bitmap, and then the
OnPaint event can obtain the lock when it needs to update the PaintBox with
the bitmap.  That way, only one is trying to access the bitmap at any given
time.


Gambit

"Phuoc Can HUA" <home+a+t+huaonline.com> wrote in message
news:3e90c1f3$1@newsgroups.borland.com...

> Now, when I move the main form over the form with the
> PaintBox very fast the image can't be restored properly. It looks
> like Windows can detect the 'invalid' area and only updates a
> small part of the PaintBox, although my procedure copies the
> entire image. That's OK. But the 'funny' thing is that the update
> segment sometimes appears at the wrong place, somtimes even
> somewhere on the screen (outside of the paintbox). Of course,
> sometimes it crashes as well :-(