[wxPython-users]How to capture multiple keydown event? Ctrl + A + B

[甜瓜]

Hi,
    I encounter a technical problem about capturing key combinations
like Ctrl + A + B. Is there any example? I remebered that there is an
article in wx wiki discussing this topic...
    Moreover, if I want to capture pure Ctrl+Alt combination, which is
no other character key pressing, the traditional wx keyevent seems no
work. How to deal with it?
    An good example is VMWare client. When you press Ctrl+Alt
combination, the mouse cursor will be released from VM client area to
normal window desktop. How do they implement this keyboard message?
    Thank you
--
ShenLei