I have an arduino in keyboard emulation mode that sends keyboard keystrokes to the computer it's connected to, the latter appending a log line in a local webpage upon receiving each keystroke. The log program is coded in C using Win32 API.
Now, since it's supposed to function at work (the idea is to get a log file online of when pushbuttons on my desk have been activated), I will be locking my computer...
How can I keep processing CTRL+ALT+key strokes from the windows lock screen?
Thanks,
Mister Mystère
This seems to work: https://www.codeproject.com/Articles/19004/A-Simple-C-Global-Low-Level-Keyboard-Hook
When you run the compiled executable, the keys A and B are detected globally even when the screen is locked.
I ended up downloading a third party lock screen and my program works in its background as it is a standard program. For those of you in the same situation, as far as I know after all that research I'm afraid you'll have to do that instead: it seems like it is not possible starting from Vista.
Related
I want to run a program on a server.
But I don't want it shoutdown immediately after I press power button.
The expected result is server could finish program properly and get the test result. Then shutdown finally.
The program running environment would be under the Ubuntu 20.04 Virtual Terminals(TTY).
I have tried some methods on the web I found (like change some system files). But it just disabled the power button function. I can't connect how to detect in my program.
I am curious is it possible to detect power button pressed or not in the program we wrote?
If it is possible, how to do?
Thank you very much!
I would have preferred to comment but I don't have enough reputation.
Have you tried to modify the /usr/share/doc/acpid/examples/powerbtn.sh script?
This page seems to describe how to proceed. But I haven't gone deep.
I am developing a C program that prints out a message. The problem with it is that when I run its .exe file, it does not run in fullscreen (until I press alt+enter to force it to full screen). I want the program to run in fullscreen itself when I run it. Is there any way I can do it?
Thanks in advance.
You could call SetConsoleDisplayMode() to force CONSOLE_FULLSCREEN_MODE. Beware that support for this has been disappearing. The last machine I owned that could still do this has been gathering dust for quite a while already. Along with the memory of the loud relay clicking sound, mixed with the high-pitched wail of the flyback transformer in the CRT.
Here is the situation. The company I work for builds this piece of software in c that can make a Windows computer act a bit like a TV. Essentially, our piece of software is meant to be played full screen and content is displayed from the internet without the user having to ever touch the computer again.
The problem is that once in a while, the system brings up pop-ups like "Your Windows system is ready for an upgrade." or "Please renew your Norton subscription" etc. which the user has to periodically and manually remove.
Is there a way to display content full screen without being bothered by those warnings?
Yah, whether or not the development community agrees, Microsoft has several standards for when and why it might be acceptable to have exclusive use of the monitor.
The most official strategy is to use DirectX in exclusive mode. This is what games do, what windows media player does in full screen video with hardware acceleration enabled, etc... If your application is multimedia intensive (as suggested by TV like functionality), you should probably be using DirectX too. Besides giving you the exclusive display access it will also increase your applications performance while lowering the CPU load (as it will overload graphics work to the video card when possible).
If DirectX is not an option, there are a great number of hacks available that seem to all behave differently between various generations of windows operating systems. So you might have to be prepared to implement several techniques to cover each OS you plan to support.
One technique is to set your application as the currently running screensaver. A screensaver if really just an EXE renamed to SCR with certain command line switches it should support. But you can write your own application to be such a screensaver and a little launcher stub that sets it as the screensaver and launches it. Upon exit the application should return the original screensaver settings (perhaps the launcher waits for the process to exit so that it returns the settings in both graceful exits and any unplanned process terminations ie: app crash). I'm not sure if this behavior is consistent across platforms though, you'll have to test it.
Preventing other applications from creating window handles is truly a hack in my opinion and pretty bad one that I wouldn't appreciate as a customer of such software.
A constant BringWindowToTop() call to keep you in front is better (it doesn't break other software) but still a little hack-ish.
Catch window creation messages with a global hook. This way you can close or hide unwanted windows before they become visible.
EDIT: If you definitely want to avoid hooks, then you can call a function periodically, which puts your window to the top of the z-stack.
You could disable system updates http://support.microsoft.com/kb/901037 and remove the norton malware.
You could also connect a second screen so that the bubbles appear in the the first monitor.
Or you rewrite it for linux or windows ce.
One final option is to install software that reconfigures your os into a kiosk http://shop.inteset.com/Products/9-securelockdown.aspx
If you don't need keyboard or mouse input, how about running your application as a screensaver?
A lot of thoses messages are trigged/managed by Windows Explorer.
Just replace it with your dummy c#/winform.
By changing the registry value
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"Shell"="Explorer.exe"
You can specify virtually any exe as an alternative to explorer.exe
That's the way all windows based (embedded) system (ATM & co) do.
There's still few adjustment (disable services you dont need / dr watson & others), and of course, you'll want to keep a "restart explorer.exe" backdoor.
But that's a good start
I'm writing a program in C and want it to have an option that will keep a mac laptop awake even if the lid is closed so processes can continue. There seems to be very little information available on this topic so I really don't know where to begin. If anyone knows how to accomplish this or where I can find more information I would really appreciate (i.e. will I need to work with the BIOS for this or are there built in functions?). Also, if it's easier to do it in another language that is fine as I'm not stubbornly set on using C.
You need to write a kernel extension for this. The OS doesn't support it by default because the laptops aren't designed to properly cool themselves with the lid closed and internal display enabled. SleepLess is a $10 utility that'll do what you want, too. If you warp the display or something, it's your own fault. :-).
If you want to write something yourself, LidSleep.kext looks like a good start (it does the opposite, i.e. sleeping on lid close) and comes with source code.
(It is possible and supported to wake up some Mac laptops with the screen closed by using an external input device.)
You can do this using the I/O Kit framework, see QA1340 listing 2 for sample code using IOPMAssertionCreateWithName to temporarily prevent sleep.
The link to LidSleep.kext listed above is not working, so I can inform that the author of NoSleep has made the source code available here, so you can see for yourself how it can be done:
https://code.google.com/p/macosx-nosleep-extension/
If your laptop is a reasonably recent model, you don't need to add anything. If you are running Lion, it simply works. If you're running an older OS you have to wake up the laptop by sending it a keystroke or mouse click from an external keyboard or mouse. See http://support.apple.com/kb/ht3131
I am testing my application (Windows 7, WinForms, Infragistics controls, C#, .Net 3.5).
I have two monitors and my application saves and restores forms' position on the first or second monitors. So I physically switched off second monitor and disabled it at Screen Resolution on the windows display settings form. I need to know it is possible for my application to restore windows positions (for those windows that were saved on the second monitor) to the first one.
I switched off second monitor and press Detect to apply hardware changes.
Then Windows switched OFF the first monitor for a few seconds to apply new settings. When the first monitor screen came back, my application became unresponsive. My application was launched in debug mode, so I tried to navigate via stack and threads (Visual Studio 2008), paused application, started and did not find any thing that help me to understand why my application is not responsive. Could somebody help my how to detect the source of issue.
Download the Debugging Tools For Windows then run adplus in hang mode. The with the resulting .dmp file open in windbg and invoke:
!analyze -v -hang
You should provide more information about what you saw in the call stack and threads windows. Which threads were running? Did you see anything that was waiting in a sleep or join? Have you tried naming your threads so that it's clearer as to what's going on when you pause (though not necessary since you can get this info from the call stack anyway... it's a convenience thing).