DPI and Scale Problem   

Hi all,

I'm using Visual Studio 2005 (.net 2) to build my Windows application.
Now, I don't understand the effect of changing screen DPI.
My application is a card designer that uses forms as body of card and 
controls on it as contents of card.
When I change DPI from 96 to 120 the controls of application forms looks 
larger, but the contents of the card looks smaller.


Please help

date: Mon, 16 Jun 2008 04:12:00 -0700   author:   A7mad

Re: DPI and Scale Problem   

Note that the screen resolution is selected and controlled by the end user, and you must
not change it.  I've had too many programs that think they have the right to select screen
resolution, and they are *always* wrong (for example, they don't work terribly well in
multimonitor situations, and don't work at all on LCD monitors).

Generally, issues about resolution deal with how the device driver for the graphics
controls the conversion of Dialog Box Units to pixels.  It is arbitrary, whimsical, and
not under your control.  If you care about how things look, you have to do your own
conversions.  Note that many display drivers lie about the resolution, and the
pixels-per-inch numbers are usually treated as science fiction, or sometimes fantasy; it
depends on a huge number of factors including how well the driver accounts for the
physical display size (usually poorly).

The one time I cared, I printed a 1" square on a transparency, had the user hold it up to
the screen, and fiddle my calibration screen until they decided that the screen was
displaying a 1" square.  This established the conversion parameters I used.  I've never
seen a program yet that could consistently get images to look right if they don't use a
technique like this.
					joe

On Mon, 16 Jun 2008 04:12:00 -0700, A7mad  wrote:

> Hi all,
>
>I'm using Visual Studio 2005 (.net 2) to build my Windows application.
>Now, I don't understand the effect of changing screen DPI.
>My application is a card designer that uses forms as body of card and 
>controls on it as contents of card.
>When I change DPI from 96 to 120 the controls of application forms looks 
>larger, but the contents of the card looks smaller.
>
>
>Please help

date: Thu, 31 Jul 2008 05:02:56 -0400   author:   Joseph M. Newcomer