?
Solved

Windows API Hook Notification when Capturing Display

Posted on 2009-05-09
5
Medium Priority
?
531 Views
Last Modified: 2013-12-03
I am writing a program that writes pixels to the main display background on windows. I can write the pixels, but I also need to know when this information is captured. I have a low level keyboard hook that is triggered when the print key is pressed. Is there any api hook or other way to be notified when any program calls CreateDC("DISPLAY", "", "", "") to get the main display window?
0
Comment
Question by:secondeff
  • 3
  • 2
5 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 2000 total points
ID: 24348274
Take a look at http://www.codeproject.com/KB/system/hooksys.aspx ("API hooking revealed") - this article explains that in detail and comes with full source code.
0
 
LVL 1

Author Comment

by:secondeff
ID: 24378119
Thanks for the very informative article. However, I did not find anything specific about detecting screen capture type events. Like I said, I can only detect the print screen button. Any suggestions?
0
 
LVL 86

Expert Comment

by:jkr
ID: 24378229
Well, you'd have to detect calls that are typical for screen capture, e.g. as you already mentioned 'CreateDC()'. The problem is now is that these might not necessarily mean screen capturing in each case...
0
 
LVL 1

Author Comment

by:secondeff
ID: 24378284
Do you know which hook type I would use to capture a CreateDC() call? I see the issue of seperating them, but it would be a good start.
0
 
LVL 86

Expert Comment

by:jkr
ID: 24378791
Well, as described in the article, an API hook - unfortunately, the kind of hooks set by 'SetWindowsHookEx()' can't do that, that's where API hooking comes into play.
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

This article shows how to make a Windows 7 gadget that extends its U/I with a flyout panel -- a window that pops out next to the gadget.  The example gadget shows several additional techniques:  How to automatically resize a gadget or flyout panel t…
In this article, I will show how to use the Ribbon IDs Tool Window to assign the built-in Office icons to a ribbon button.  This tool will help us to find the OfficeImageId that corresponds to our desired built-in Office icon. The tool is part of…
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
Watch the video to know how one can repair corrupt Exchange OST file effortlessly and convert OST emails to MS Outlook PST file format by using Kernel for OST to PST converter tool. It can convert OST to MSG, MBOX, EML to access them. It can migrate…

590 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question