CEGUI的事件監聽器又是如何實現的呢?
對于控件,每種控件有自己的事件,如:EventKeyUp等;每個事件后面可以掛著N個事件的回調方法;
event:function1,function2......
對控件訂閱事件,如button->subscribeEvent(CEGUI::Windos::EventKeyUp,CEGUI:Event::Subscriber(&function,this));
把事件EventKeyUp注冊到button中,并且在事件響應時回調函數fuction

內部實現機制是怎么樣的呢?內部好像通過一個Map來查找到這個事件,但是又是如何響應到function的呢?哪位大哥指點下?

原來是一步步調用.我們設置一個斷點在function,在DEBUG模式下"調用堆棧"
virtual bool operator()(const EventArgs& args)
    {
        return (d_object->*d_function)(args);
    }
再根據多態性
  bool operator()(const EventArgs& args) const
    {
        return (*d_functor_impl)(args);
    }
在事件類中
void Event::operator()(EventArgs& args)
{
    SlotContainer::iterator iter(d_slots.begin());
    const SlotContainer::const_iterator end_iter(d_slots.end());

    // execute all subscribers, updating the 'handled' state as we go
    for (; iter != end_iter; ++iter)
        args.handled |= (*iter->second->d_subscriber)(args);
}
事件設置:
void EventSet::fireEvent_impl(const String& name, EventArgs& args)
{
    // find event object
    Event* ev = getEventObject(name);

    // fire the event if present and set is not muted
    if ((ev != 0) && !d_muted)
        (*ev)(args);
}
void EventSet::fireEvent(const String& name, EventArgs& args, const String& eventNamespace)
{
    // handle global events
    GlobalEventSet::getSingleton().fireEvent(name, args, eventNamespace);
    // handle local event
    fireEvent_impl(name, args);
}
再到Window窗口中
void Window::onMouseClicked(MouseEventArgs& e)
{
    fireEvent(EventMouseClick, e, EventNamespace);
}
再到
bool System::injectMouseButtonUp(MouseButton button)
{
 ....
 while ((!ma.handled) && (dest_window != 0))
        {
            ma.window = dest_window;
            dest_window->onMouseClicked(ma);
            dest_window = getNextTargetWindow(dest_window);
        }
 ....
}
最后在Windows 消息處理中
LRESULT CALLBACK Win32AppHelper::wndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch(message)
    {
        .....
        case WM_LBUTTONUP:
        CEGUI::System::getSingleton().injectMouseButtonUp(CEGUI::LeftButton);
        break;
        .....
    }