Re: How to handle Windows 7 screen resolution change?

From:
"David Ching" <dc@remove-this.dcsoft.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Tue, 20 Apr 2010 22:13:49 -0700
Message-ID:
<uSVPuFR4KHA.4416@TK2MSFTNGP06.phx.gbl>
"Lewis Z." <lzhou8@gmail.com> wrote in message
news:2463fe87-ed85-49fd-9779-bea17da4612c@c36g2000yqm.googlegroups.com...

Joe, thanks for the reply. I handled the drawing of the background
image in the EraseBackground msg handler. After I figured out the
WM_DISPLAYCHANGE, I called RedrawWindow in this msg handler. It didn't
help all the time. Sometimes I still saw the missing image.


It's perfectly fine to be drawing your image in OnEraseBkgnd(). But by
chance did you cache the rect of the image? The rect would need to be
recomputed when the display is changed. Also, try calling Invalidate()
instead of RedrawWindow().

I have basic OnPaint function, meaning it just calling
CDialog:OnPaint(). I commented out my OnPaint function. Now the
background image is diaplayed all the time whenever the display
setting is changed. But new problem shows up. Calling SetDlgItemText()
is causing problems. It shows some garbled texts unless screen is
refreshed. (I have a timer periodically displaying texts with null
brush to show transparent texts.)


Oh if you're using transparent brushes, all bets are off, since there is no
way to erase the current contents when the area needs to be repainted from
scratch. The way to start from scratch is to do ShowWindow(SW_HIDE);
followed by ShowWindow(SW_SHOW) on the offending dialog controls.

-- David

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