[fpc-pascal]Re: Win32 windows update

Ingmar Tulva juss_it at ut.ee
Wed Oct 23 16:39:49 CEST 2002

On Wed, 23 Oct 2002, Hans [iso-8859-1] MÃ¥rtensson wrote:

}I'm still wondering why I can't send a wm_paint message with a call to
}postmessage, but never mind, this works.

You can, the window procedure gets the WM_PAINT and processes it, but
there is a concept called 'update region' in Windows. Op-sys doesn't allow
drawing outside it. InvalidateRect adds a rectangle (or whole window) to
the update region. When Windows finds that the update region of a window
is non-empty, it sends WM_PAINT itself, so usually you needn't worry about


Ingmar Tulva

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