Re: Displaying a bitmap

From:
"Igor Tandetnik" <itandetnik@mvps.org>
Newsgroups:
microsoft.public.vc.language
Date:
Mon, 9 Jul 2007 23:11:44 -0400
Message-ID:
<#1QcNAqwHHA.4640@TK2MSFTNGP03.phx.gbl>
"Wang" <Wang@discussions.microsoft.com> wrote in message
news:027582C5-00CF-417E-B6B2-07195569F3A7@microsoft.com

However, I can get the bitmap displayed only if I write those code
under WM_PAINT. I tried to do it under other message handlers but
doesn't work. But for example, what if I want the bitmap to display
when a button is clicked or something like that, but not initially
displayed when the app launch?


You have to maintain enough state to be able to regenerate the
appearance of your window at any time. For example, you could keep a
boolean flag that indicates whether the bitmap should be drawn or not.
You never know when, say, another window that covers yours is moved and
the OS asks you to repaint.

When the state changes, call InvalidateRect to mark a portion (or all)
of your window invalid. The OS will soon turn around and send WM_PAINT
to your window, to give it a chance to repaint itself in new state.
--
With best wishes,
    Igor Tandetnik

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