Holy cow, I wrote a book!
"Why would somebody ever want to do that?" you might ask. Well, this is a common appearance
for floating toolbars. (But aside from that case, I can't think of any other valid
reason to draw a window as active even though it isn't.)
Fortunately this is easy to do. Just add this line to the WndProc of
our scratch program:
case WM_NCACTIVATE: if (wParam == FALSE) wParam = TRUE; break;
This says, "If Windows asks me to paint my caption bar in the inactive state, turn
around and draw it in the active state."