ubuntu 9.10 + X11 + qt4.5
根据X文档:Only the error-handling routine XErrorHandler (or the one you define) receives error events.
These events cannot be selected or received by windows.
根据qt文档:bool QWidget:: x11Event ( XEvent * event ) [virtual protected]
This special event handler can be reimplemented in a subclass to receive native X11 events passed in the event parameter.