We help IT Professionals succeed at work.

Check out our new AWS podcast with Certified Expert, Phil Phillips! Listen to "How to Execute a Seamless AWS Migration" on EE or on your favorite podcast platform. Listen Now

x

GetDeviceCaps under different solutions

titz
titz asked
on
Medium Priority
746 Views
Last Modified: 2010-04-06
hi,

under D3 and WIN98 there is following problem:
I use the function GetDeviceCaps for some calculations
about space on then screen.
For example: i want to draw a rectangle and its proporties
(x,y,w,h) are given in mm. Therefore i use the
GetDeviceCaps to get the size of the screen in mm and
the size in pixels and calculate the translation-factor
of the pixels per mm.
Its works fine until i realized that under WIN98
the size of the screen in mm depends on the solution !
What is that ?? My screen has not shrunk !

Here is some code :

dc:=getdc(handle);
w:=getdevicecaps(dc,horzsize);
w1:=getdevicecaps(dc,horzres);
wfactor:=w1/w;

w1 is 640 in solution 640 x 480 and
w  is 135 .
w1 is 800 in solution 800 x 600 and
w  is 169 .
Why does w depend on the screen-solution ?

thanks
titz

Comment
Watch Question

Commented:
will you please test it with handle = 0 and report the result
As I can see you simple get the Width and Height of your form... When use dc := GetDC(Handle); it will get the DC of the form... If you want to take the desktop's DC you need to use DC := GetDC(0); as Inter suggested...

Regards,
Viktor Ivanov

Author

Commented:
hi inter and viktor,

i tried with
dc:=getdc(0);

the results for w and w1 are exactly the same.

titz

you need to have HORSIZE and VERTSIZE /or was it VERSIZE..Don't remember....

Cheers,
Viktor

Author

Commented:
hi viktor,
there is a misunderstanding:
the results for w and w1 are the same as in my example !
That means : dc:=getdc(0) is no solution for my problem.
Its still existing!
hope for help !
titz

Commented:
Please, take a look at my previous question - it had a happy end, so I hope you can find an idea or two there...

https://www.experts-exchange.com/Q.10067947

--Matvey
How about this one>???

DC := GetDC(GetDesktopWindow);

Does it work???

Cheers,
Viktor
Unlock this solution with a free trial preview.
(No credit card required)
Get Preview

Author

Commented:
hi viktor,
thanks for your efforts. But your last try with getdc(getdesktopwindow) shows the same effect as before with getdc(0). Always different values for w and w1.

hi roadrunner,
thanks for your thoughts. i will do it in this way, matvey too received this answer in his question some time before.
thanks
titz

Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a free trial preview!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.