Detect Screen DPI Change

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4 total messages Started by JD Wed, 30 May 2007 10:22

#1889

Author: JD
Date: Wed, 30 May 2007 10:22

6 lines
914 bytes

Is there some way that I can detect a change in the screens
density of pixels per inch (like when the user changes the
resolution using the ControlPanel)?

~ JD

Re: Detect Screen DPI Change

#1891

Author: Giuliano
Date: Wed, 30 May 2007 10:38

22 lines
1386 bytes

Il 30 May 2007 03:22:58 -0700, "JD" <nospam@nospam.com> ha scritto:

>
>Is there some way that I can detect a change in the screens
>density of pixels per inch (like when the user changes the
>resolution using the ControlPanel)?
>
>~ JD

You could try to see if TApplicationEvents::OnSettingChange
of the TApplicationEvents component resolves your problem.

In fact, the online help states:

<<Use OnSettingChange to respond when Windows informs the   application that a
system-wide setting or policy has changed.>>     

So, I think it could help you.    

Regards    

Giuliano

Re: Detect Screen DPI Change

#1890

Author: Mike Collins
Date: Wed, 30 May 2007 11:42

24 lines
1474 bytes

System sends a WM_DISPLAYCHANGE message to all windows when the display 
changes. see:

 http://msdn2.microsoft.com/en-us/library/ms534847.aspx

Just intercept this message by defining your own wndproc for the main form 
and looking for this message.  Then you should be able to be informed when 
the screen settings change

HTH

Mike



"JD" <nospam@nospam.com> wrote in message 
news:465d5082$1@newsgroups.borland.com...
>
> Is there some way that I can detect a change in the screens
> density of pixels per inch (like when the user changes the
> resolution using the ControlPanel)?
>
> ~ JD
>

Re: Detect Screen DPI Change

#1898

Author: JD
Date: Thu, 31 May 2007 12:35

11 lines
1257 bytes

"Mike Collins" <its@TheBottomOfThePost> wrote:
>
> System sends a WM_DISPLAYCHANGE message to all windows when
> the display changes.

That's the way I went because only a secondary form is
interested and I wanted to keep the code encapsulated.
Using a TApplication event would break the encapsulation.

~ JD

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