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can I programmatically access pixel color on the screen?

in other words, I am thinking of an app that could sort of "see" my entire computer screen. Well, I can programmatically find out width and height of the screen in C#, so now the only thing missing is actually finding out the color of the pixels by their absolute coordinates. Does anybody know how to do that?
Michael L Send private email
Thursday, April 30, 2009
 
 
You can BitBlt the contents of the screen to a bitmap. I haven't done it in C#, but it was easy enough when I did it in C++.
sloop Send private email
Friday, May 01, 2009
 
 
That would be a fun security violation, if you could paint over another application.
Scorpio Send private email
Friday, May 01, 2009
 
 
I once wrote an app to do something similar for a demo -- took a screenshot, popped open a top-level window and painted the snapshot on it, then did lots of stuff underneath to the running apps where no one could see, then removed my top-level window when done.  Worked like a charm :)

Similar approaches are a great source of practical jokes.  One thing you can do is take a snapshot of a coworker's screen and set it as their background image.  Then minimize all the apps.  Somehow none of their apps respond when they click on them :)
Doug Send private email
Friday, May 01, 2009
 
 
Search for "screen capture" on codeproject.  There are several sample applications that should get you started, like this

http://www.codeproject.com/KB/vb/Screen_Shot.aspx
Jason Send private email
Friday, May 01, 2009
 
 
"...take a snapshot of a coworker's screen and set it as their background image"

Yeah, that reminds me of a series of practical jokes that were played on a team-leader on a project I used to work on.  As well as the screenshot as background image, the LAN admin guy changed his account to require a change of password every day, each with a minimum of 16 characters.

It is amazing what some people will accept if they think it is "official policy".
Scorpio Send private email
Monday, May 04, 2009
 
 

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