C# – Capture any kind of keystrokes (aka keylogger), preferably c# .net but any kind will do

.netc++capturekeystrokekeystrokes

I need to capture everything that I type on my keyboard and then store it in numerous ways. I'd prefer it to be written in C# for .Net, but anything will do really.
My reasons to write this "keylogger" are simple:

Recently I became an owner of a Peregrine gaming glove. It's a very cool thing that allows you to issue commands by making gestures with your fingers, and at the same time, its a very thin glove so you can type with that hand with little discomfort.

Also, I have found a nice program called AutoHotkey that can severely boost your productivity by making macros for like any action. You can bind any key to any other key or series of keys or commands.

The problem is, you cannot tell it just like that "this is what I'm doing most" and "this is what I'm rarely using." Really, can you tell what key do you use more, page down or down? Do you use alt+tab more frequently that escape or layout switch (ctrl-shift or alt-shift)? I cannot tell that. I cannot tell which actions should I automate or switch to the more easy interface, without statistical data.

So I want to write a program to run in the background and log everything I type. This program will then store first, second and third order histogram of my actions (like, it will store how many times I pressed any single key, like entering, how many times I pressed a succession of two keys, like alt and then tab, and how many times I pressed a succession of three keys, like ctrl, alt and then deleted or ctrl,shift and then escape)

Then, after some time spent working/playing/whatever, I'll have information on what kind of actions should I try to bind to that interface (the glove) or automate with AutoHotkey program, to improve the speed of interacting with a PC.

In other words, simple science experiment, just for fun and progress 🙂

Best Solution

Old question but...

In Windows you can use the APIs of the user32.dll.

For a very simple keylogger you can use the method GetAsyncKeyState() checking whether each character of the ASCII table is pressed.

The whole code for a very simple and stupid keylogger written in a Console Application would be:

[DllImport("user32.dll")]
public static extern int GetAsyncKeyState(Int32 i);
    
static void Main(string[] args)
{
    while (true)
    {
        Thread.Sleep(100);
    
        for (int i = 0; i < 255; i++)
        {
            int keyState = GetAsyncKeyState(i);
            // replace -32767 with 32769 for windows 10.
            if (keyState == 1 || keyState == -32767)
            {
                Console.WriteLine((char)i);
                break;
            }
        }
    }

KeystrokeAPI

For those who are looking for something more robust and cleaner I've created an API that makes it easy. You only need to do this:

api.CreateKeyboardHook((character) => { Console.Write(character); });

More details here: https://github.com/fabriciorissetto/KeystrokeAPI

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