title: Capturing keyboard input without focus on the programwindow
body: <p>I am doing a VoIP client and I want to start/stop on WM_KEYDOWN and WM_KEYUP messages for a certain input, say K. When the main window has focus, this is np, but how do I enable it outside of the window? For example, if the window is not in focus and I'm just looking at the desktop or am in a videogame. How does one perform something like this? I am not sure where to begin.</p>
  
  <p>Also -- I guess you somehow has to poll every input even outside the program, is that expensive?</p>
  
  <p>win32 c++ btw</p>