I'm writing a program that I want to run when the user is "idle" (I.e. No input from the user - not moving the mouse, or typing anything). I have taken care of detecting if the mouse is moving (through storing the mouse position as a variable and comparing the current position to that variable at a later time), but what I can't figure out is how to detect keyboard input.
I know that if the user is typing in the form itself, I can use event listeners (KeyDown, KeyPressed, etc.), but I want this program to detect keyboard input anywhere on the computer, in any program.
Is there a way to accomplish this? All my research has yielded ways to check inside the form, but not globally.
Note: Not sure if this matters, but I don't care what the user is typing (what keys are being pressed). All I need to know is that there is keyboard activity.
Thanks in advance!
What you're looking for is considered a Global Keyboard Hook.
A sample with explanation and source:
here
Edit: In terms #FᴀʀʜᴀɴAɴᴀᴍ answer, it would be improper to grab using GetLastInputInfo as system calls (SendInput(), keybd_event(), etc) all will trigger it as well, so that doesn't mean the user is technically there.
Related
I have an application where I have multiple keyboards connected through USB.
I need to hook a specific keyboard to get the keypress directly into the software, even if this one is not on the foreground. This so far works based on this project. The other keyboards shall work as normal.
Although it seems by using Direct Input, it is not possible to stop propagation (we don't want other apps to get that particular keyboard input).
Concerning Global Hook, it can block the keypress system-wise, but it is impossible, as far as I know, to identify the source of the keystroke (which keyboard it is from) and thus to selectively block them.
There is another project, here, that combines the two, but it is quite messy and heavy.
Is there a better way to achieve this? I am surprised that simple task is so complex.
If you are going to make the app windows only, you should look into Windows raw input api
It isn't that complicated.
I was making a program that changes the desktop background, but there is no need to do this when the user is not on the desktop.
I was wondering if there was a way to detect if the user was on the desktop.
I was also thinking an alternative could be checking whether the user is on any other processes, but I don't know how to do this either.
(I would happily provide my code if necessary)
I'm sorry for posting such a broad question, I hope there is a way to do this though.
Thanks to anyone who can help!
If you want to check application in idle condition then you have to do below:
Add a timer control to your application.
Subscribe to mouseover and keydown events - when they fire, reset the timer.
When the timer fires (ie mouse hasn't moved and key's haven't been pressed for x amount of time), write your logic.
And If want to check idle condition of desktop then below references will be useful for you:
Detecting that the user is away from the PC with .NET
Detecting that the user is away from the PC with .NET
http://www.codeproject.com/KB/cs/ApplicationIdle.aspx
http://msdn.microsoft.com/en-us/library/system.windows.forms.application.idle.aspx
http://ellisweb.net/2008/02/detecting-application-idle-state-in-windows-forms/
I have to write an application in C# that listens to any keys being pressed. In actuality I have a bar code scanner sending the "key pressed" event, and I need to listen it... what it does from there is beyond the scope of my question.
My security requirements are that there is not allowed to be any sign-on to the machine in any way shape or form AND this must run as a windows service. The user will start the machine and walk away (i.e., no desktop session).
I'm assuming I'm going to have to go unmanaged for this.
Given the security requirements is this even possible? If so, any pointers on where to start would be great.
Thanks in advance,
Jay
Try keyboard and mouse hook
http://www.codeproject.com/KB/cs/globalhook.aspx
You will have to learn pInvoke with combination of learning how to look for the right events produced at the lower level of OS. By calling into user32.dll using pInvoke your managed code can filter those events through the hooks.
http://pinvoke.net/default.aspx/user32.SetWindowsHookEx
If you need to see keyboard presses for all apps, system-wide Hooks would be the way to go normally, but the problem is that the security changes in Vista and above make hooks rather less useful. A process cannot hook another process at a higher integrity level, so there's no guarantee you will see all events.
However if you only need to see events going to a particular app - the one reading the bar codes - then provided you can identify that process, a thread-specific hook will suffice and the integrity question will not arise.
Is there a way to start a process in a separate instance with it's own mouse and keys that don't interfere with the use of other processes.
For Example: Let's say I want to make a program that automates a program and it requires clicking on locations and trying in keys. While this is happening I want to be able to do other things on the computer like nothing is happening.
Attempt At Clarity:
So this separate instance would be given inputs for the program based on what it sees or something like that. No separate output from the user. More like the program is running the process in the background while youre using your computer like normal
You can use .NET for input simulation using WinForms.
For keyboard input you need SendKeys and for the Mouse you can use Cursor. Although it should be noted that the OS - usually - only includes one mouse pointer, and so setting it's position is machine wide.
For a better simulation of mouse input, you will need to resource to p/invoke. The recommended pattern is to use SendInput.
Alternatively, you could look for existing solutions that emply this technique, such as InputSimulator.
Is it possible to programmatically create input events in c#.
I want to be able to simulate any input, such as pressing a button on the keyboard or moving the mouse pointer from my application. The events generated by the application need to behave (preferably) in exactly the same way that an actual key press for instance does (post an event to the system event queue that is given for applications to process).
I seem to be unable to find any documentation about doing this from c# code after googling for an hour.
As always, any answers will be greatly appreciated.
You can try SendKeys for keyboard input. For more control, and mouse events too, you should P/invoke SendInput().
Be warned that this is difficult to get right and you may find alternative approaches more amenable.