title: Create a fully transparent WPF window to capture mouse events
body: <p>I'm trying to trap mouse events in WPF by using a topmost, transparent non-modal window.  I'm finding that this works fine if the opacity of the window is 0.01 or greater and it has a background color, but when the opacity is set to 0 it no longer receives mouse messages.  Is there a way make this window look fully transparent and still get mouse input?</p>