Low level keyboard input from Windows

Question

What win32 calls can be used to detect key press events globally (not just for 1 window, I\'d like to get a message EVERY time a key is pressed), from a windows service?

Answer 1

You want to use Win32 Hooks. In particular a keyboard hook.

You can read more about it here

The type of hook you want is WH_KEYBOARD and you can set it via the Win32 API SetWindowsHookEx.

Basically windows will call a function in a dll that you create everytime a key is pressed in any application system wide.

The hook will call your function which will have this interface:

LRESULT CALLBACK KeyboardProc(      
    int code,
    WPARAM wParam,
    LPARAM lParam
);

More information about this callback here.

With windows hooks you can not only track system wide events across all processes, but you can also filter them and stop them altogether.