Screenshot algorithm is giving blank areas in Win10 - worked fine in all other Windows versions

Question

I used the following method to take a screenshot of all the monitors. It works flawlessly, but I just upgraded to Windows 10 and am seeing a major issue. I am getting blank/transparent areas.

Regular screenshot using PrtScn: https://i.stack.imgur.com/octsD.png

Using my algorithm: https://i.stack.imgur.com/NivwE.png

my algorithm details

My algorithm is called from a Firefox, and it takes a screenshot after 5 seconds. At the time of screenshot, Notepad++ was focused.

EnumDisplayDevices
CreateDC with lpszDriver and lpszDevice obtained from step 1
CreateCompatibleDC on result of step 2
CreateDIBSection on result of step 2
SelectObject results of step 2 onto result of step 4
BitBlt

Here is the WinAPI calls from my code, it is in js-ctypes:

ostypes.API('EnumDisplayDevices')(null, iDevNum, lpDisplayDevice.address(), 0);
var hdcScreen = ostypes.API('CreateDC')(collMonInfos[s].otherInfo.lpszDriver, collMonInfos[s].otherInfo.lpszDevice, null, null);
var hdcMemoryDC = ostypes.API('CreateCompatibleDC')(hdcScreen); 
var hbmp = ostypes.API('CreateDIBSection')(hdcScreen, bmi.address(), ostypes.CONST.DIB_RGB_COLORS, pixelBuffer.address(), null, 0);
var rez_SO = ostypes.API('SelectObject')(hdcMemoryDC, hbmp);
var rez_BB = ostypes.API('BitBlt')(hdcMemoryDC, 0, 0, w, h, hdcScreen, 0, 0, ostypes.CONST.SRCCOPY);
// i then draw pixelBuffer to a html5 canvas

Has anyone else experienced these blank spaces? Anyone know solution?

What happens when you do this from a normal app and not inside firefox — David Heffernan, Nov 28 '15 at 15:31
Thanks @DavidHeffernan for the quick reply, I had passed out it was 5am my time :P Im not sure how to do this from normal app. Can you please tell me how I can try. — Noitidart, Nov 28 '15 at 20:56
Oh I don't have a C or C++ environment but I'll download VS2013 and update you. :) — Noitidart, Nov 28 '15 at 22:21
I think it's foolish to do this stuff without access to native tools — David Heffernan, Nov 28 '15 at 22:25
Hey @DavidHeffernan I tried it from regular app, and it is also giving me blanks :( here is my cpp - https://gist.github.com/Noitidart/e7aaa201798d019e92b2 — Noitidart, Nov 30 '15 at 08:40
So this makes it a pure winapi question. You'd be better making a new Q with a full mcve in C++. Although I bet the question has been asked before. — David Heffernan, Nov 30 '15 at 13:43
Thanks @David I created it here - http://stackoverflow.com/questions/34006966/the-dependable-screenshot-method-gives-transparent-areas-in-windows-10 — Noitidart, Nov 30 '15 at 20:03

Screenshot algorithm is giving blank areas in Win10 - worked fine in all other Windows versions

my algorithm details

0 Answers0