Question

I can’t find on google what reference I must use to be able to use RegisterHotKey. What is it?

And while on the topic, should I use RegisterHotKey if I am trying to create an application which listen for key combination in the background?

Answer 1

You need a DllImport, not just a reference. You can find tons more information at pinvoke.net.

In short, if you add:

[DllImport("user32.dll")]
private static extern bool RegisterHotKey(IntPtr hWnd, int id, int fsModifiers, int vlc);

somewhere in your program, the only remaining tricky part is coming up with the hWnd to register to handle the key. The sample code linked at pinvoke.net above should help you use the DllImport.