I'm attempting to automate moving between different time zones while I travel and was curious whether someone knew how to update the "Additional Clocks" setting by using the Windows API/SDK. I'll be using .NET and C# but would definitely be happy with the raw API calls as well. Thanks!
That's not how it works. The winapi would grow gargantuan if there was an api for every single little tweak dialog like this one. Instead, the dialog changes registry keys, keys that are later read back by whatever code displays the clock.
You can find them by running SysInternals' ProcMon. Start it just before you click the Apply button, stop it right after that. You'll have little trouble finding the HCKU\Control Panel\DateTime\AdditionalClocks being used in the trace. Mapping settings in the dialog to registry values is pretty straight forward.
Hacking registry keys that belong to Windows is pretty iffy. But you'll get away with it as long as you don't hope this still works in the next version in Windows. Actually changing them might require a logoff and logon to make the changes effective, I didn't try that.
FWIW here is a PowerShell cmd that gets the additional clocks setting from the registry:
Get-ChildItem -Path "HKCU:\Control Panel\TimeDate\AdditionalClocks"
Related
I'm working on an app (Written in C#) that have a setting to run on KIOSK mode. I've just an challenge here which is disabling Ctrl+Alt+Del combination Event.
There is no right answer in the similar past posts. Please let me know about the right action.
Considering, my code is working with registry keys to disable/enable options, if you know any registry key,it will be more helpful.
CTRL+ALT+DEL is the secure attention sequence of Windows NT (and its derivatives like Win7). It is the one key combination that is guaranteed to get the OS's attention. The whole point of the SAS is that it can't be intercepted or stopped by user programs.
One security issue it addresses is that of a false login screen: consider a screen that looks exactly like the normal Windows login screen. There's no way to tell that it's a fake just by looking at it. But, if you're in the habit of always pressing CTRL+ALT+DEL before logging in (there is an option to always require it for the legitimate screen), pressing the SAS on a false login screen will bring up task manager or the secure attention screen (with the log off, change password, etc options). The real login screen doesn't do that; it just stays there on the screen. As long as the OS itself isn't replaced or compromised, CTRL+ALT+DEL will protect you from false login screens. If a user program could intercept the SAS, it wouldn't be worth anything.
The SAS was baked into the Windows NT design right from the beginning (it was in the first release in 1993), so getting around it won't be easy. I'm sure there are keyboard filter drivers-- or something to intercept that sequence-- that are designed for kiosk use.
It is not possible to capture CTRL+ALT+DEL, it is so by design in all Windows systems. This is a security issue, if the user hits CTRL+ALT+DEL, he or she should be certain that it is the operating system and not some application (possibly a password-catching trojan) that responds to it.
I guess to capture CTRL+ALT+DEL you would need to write a device driver of some sorts.
Edit: Also see This answer. I did not try it, but the question is fairly similar.
Although it is sort of possible, it is not an easy task and not something that can be done in C#. This Article will show you how to disable CTRL+ALT+DEL using group policy editor. To permanently disable the combination though, you will either need to write your own keyboard driver or write your own GINA stub (Graphical Identification and Authentication).
It is possible to pick up the CTRL+ALT+DEL combination, but not to disable it.
I tried to disable it with SetWindowsHookEx and WH_KEYBOARD_LL and you can successfully get notified when CTRL+ALT+DEL is pressed, but you cannot do anything about it.
It is possible to block CTRL+ALT+DEL combination. However, you can't really disable it. As far as I know, there are two possible methods.
Remapping the keyboard layout. There is a registry binary key that allows you to remap keyboard layout:
HKLM\System\CurrentControlSet\Control\Keyboard Layout\Scancode Map
Please check this out: Disabling Windows Hot Keys
This method can be dangerous, but I haven't noticed any side effects this method can cause. The CTRL+ALT+DEL combination is handled by winlogon.exe. If your process has administrative privilege, you can suspend winlogon.exe. Hence, it cannot process the hotkey and nothing will happen if the user presses CTRL+ALT+DEL.
Please check this out: C++ code to disable CTRL+ALT+DEL.
You will need to do some P/Invoke, in user32.dll, there's a method called SystemParametersInfo, check out these resources for more info
http://pinvoke.net/search.aspx?search=SystemParametersInfo&namespace=[All]
http://msdn.microsoft.com/en-us/library/windows/desktop/ms724947%28v=vs.85%29.aspx
I did something similar a long while back, but no longer have the code, though I did find this (it's in vb6), but it shouldn't be too hard to get the idea and translate to .NET
http://www.developerfusion.com/code/1021/how-to-disable-ctrlaltdel/
I have what seems to be a common problem. I am running Windows 7 Home Premium on one of the most awesomest computers (when it was bought last year) and certain visual effects just automatically turn themselves off.
My average user experience rating is high, so it doesn't explain why this happens. The only feature that ever gets turned off is the 'Show window contents while dragging' option. And it really annoys me.
There are currently no working solutions to this problem online. Other than to "there must be a conflict with another app installed on your machine."
And yes, I do know what app is causing this conflict. It's my bloody Internet Provider's software - you know... that app that you absolutely MUST have open at all times when you're connected to the net.
So, I had a thought. What if I could subscribe to an event so that my app that runs in the background will detect when this 'show window contents while dragging' option is turned off - and then my app will simply turn it back on again.
When I do this manually, it seems to stay in effect for about an hour or two, then it gets switched off again.
Is it possible to handle these types of events, and re-start certain visual effect features? If so, are there any resources on this?
I have not been able to find anything on this sibject yet.
Yes the WM_SETTINGSCHANGE message is sent to all windows when a system setting is changed. Then you can call SystemParametersInfo with SPI_GETDRAGFULLWINDOWS to determine if the "Show window contents while dragging" is disabled and use SPI_SETDRAGFULLWINDOWS to enable it.
So all that you will need to do is create an application with a form (that can even stay hidden) and override the forms WndProc and handle the WM_SETTINGSCHANGE message and call SystemParametersInfo using p/Invoke. The p/Invoke definition for SystemParamtersInfo is available at pinvoke.net
Altough what may be easier is change security on the HKCU\Control Panel\Desktop\DragFullWindows registry value so that it can't be changed.
I am working on a program. In testing it on Win7(32-bit, don't know if it will be the same in 64-bit) I found a problem.
Now my problem is that some of the functionality does not work(like the right click doesn't show options or the program takes long to react). If however I set up a the compatibility mode it works fine. I mainly see this problem in Microstation, but it does appear in other places as well.
My question is as follows, is there a way to set these settings(like the check boxes) programmatically from C# ?
This might be necessary in cases where we do not do the installation of the program, to insure that it works on every pc it is installed on. Let us assume that during the installation the program has admin rights. (would it be needed to do this??)
this has nothing to do with Internet Explorer. i wanted to add a picture, but i dont have enough rep yet
There is no way to change this while the application is running, you have two choices to handle this issue:
Modify the installer to create shortcuts that have the compatibility mode flag set to whatever you need
You can manually manipulate the registry to force an executable to use compatibility mode, your application will require admin rights todo so + will need to restart afterwards
Here it's explained how todo it manually, you simply have to do it programatically:
http://kb.winzip.com/kb/entry/139/
In general I discourage you from doing either, fix your bugs instead.
I have to run my C# application that I wrote it recently on several computers with window 7 operating system. Here is a big challenge with it, Application must run on startup and user must not be able to work with anything else such as windows hotkeys, other applications, some directories and etc.
Considering I don’t want to kill any process or service as less as possible, Please give me the best solution.
Thanks and waiting
Maybe A little more information will help
did you see Devices like ATMs or Medical devices that window is running on? Those devices don't allow user to manipulate with desktop or anywhere else, I want their solution. . . my Application Will run as a device handler(A Medical Device in Operating room).
You probably shouldn't write such an application in the first place (nagware?).
Anyway. I think what you are looking for is actually "kiosk" software. Here is blog entry that describes how to lock down the computer to effectively run in "kiosk mode".
Note however, that not every application can (or should) be used in that mode. Either because it has loopholes that still allow you to do thing (for example the file open/save dialog still allows you to create directories or navigate the file system), or because they were simply not designed with that goal in mind.
This sounds actually like a (very) bad idea to me...
You could probably hook every Keyboard event so you disable OS shortcut (Windows + D, Windows + E...). See here.
Also hide the Windows taskbar.
Make sure your application starts with Windows.
This sounds a bit hacky to me...
A program with the properties you mention is called a (very restrictive flavour of) shell. So you need to register your program as a shell (instead of explorer.exe) for the poor, poor user you want to restrict.
You might look into using a local group policy to enforce this restriction. Check this out.
How can I disable Print Screen functionality while my WPF application is running?
The use-case is that my client wants to avoid unnecessary replication of valuable patient-centric data from the outside world and they provide the physical security to keep people from taking data through non-digital means.
Okay, it is possible, and could indeed be useful if your application is deployed in an environment where a camera is not available to the user.
First of all, I used the RegisterHotKey and UnregisterHotKey API calls, documented here http://pinvoke.net/default.aspx/user32.RegisterHotKey as described in this rather old article here http://msdn.microsoft.com/en-us/magazine/cc163713.aspx.
I registered the IDHOT_SNAPDESKTOP hotkey in the Window_Load event and unregistered it in the Window_Closed. Trying to do this in the constructor gave me problems getting a consistent handle with the WindowInteropHelper(this) method.
If you'd like to do more than just ignore the keys you can set up a windows message handler, making a kind of WndProc using,
HwndSource source = HwndSource.FromHwnd(<handle>);
source.AddHook(<WndProc>);
making the handle as described above, and the WndProc implementation yourself.
As yet, I don't know how to "not" handle the hot key and get windows to perform its normal behaviour except, of course, by unregistering the hotkeys.
Its not very elegant or "WPF" but it worked for me.
As #ghord comments
The use of EnsureHandle() looks useful for getting a handler in the constructor.
It's not possible to disable printing, and even if it were possible, it would be easily circumvented by a cell phone camera. Many are in the megapixel resolution range, making it quite easy for someone to get the information they want.
If you want to disable the Print Screen Key on your keyboard, Jodrell's answer gives a way of doing that (understanding that it's not going to keep people from printing, and a determined user will find a way around that).
Really, it all comes down to trust. If an employer can't trust their employees not to remove data that is already protected by law in most jurisdictions (HIPAA in the USA), then there's a bigger issue at stake.
Easy:
Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().IsScreenCaptureEnabled = false;
Simply speaking, you cannot. "Print screen" just copies the pixels on the screen to the clipboard, and is not part of your application.
Basically you can hook to the ClipBoard events and then set the image copied to null if someone does it. So they can copy the image but it will be reset:
Have a look at this:
Clipboard event C#
Alternatively in a timer, check the content of the clip board and clear it as soon as it is set to a picture.
No, No way to do that. Even if you capture the Print Screen key in your application user might set focus to some other application and then do the Print screen(having your application on side etc.).
Only way would be to create a dummy application in background which captures all keystrokes using Keyboard Hooks and filters Print Screen, but that will happen for all applications not just yours. And moreover as George said user can use cellphone camera too!
I think Microsoft Rights Management System can help. Give it a try. Following is the link:
Microsoft Rights Management System
The only way I can think of is to use the native Windows API (SetWindowsHookEx) to catch all keystrokes and filter out the PrintScreen key. However this would involve creating a native (i.e. unmanaged) DLL to actually do the keystroke processing.