问题
Is it possible to receive a mouse click even in a Qt application, evaluate it, and if necessary, let it fall through to whatever might happen to be below the Qt application window?
Note that Qt::WA_TransparentForMouseEvents doesn't facilitate evaluating the click before passing it through.
And since the click evaluation incorporates some dynamic logic, it is not applicable to set a static mask either, on top of this having a visual impact as well.
Ideally, I would like a way to selectively allow the mouse click to pass through the application window in a platform portable way, ideally from QML and without bringing in the widgets module, or at the very least, without involving digging into private C++ internal APIs.
回答1:
Qt::WA_TransparentForMouseEvents is used to filter mouse events out. The name is a bit of a misnomer: it allows widgets that would otherwise consume mouse events, not to consume them. E.g. you could make a button not notice any mouse events. If you're writing a custom widget, there's never any need for this attribute, since it's up to you to inspect the mouse events and simply not handle them: they are automatically passed to the parent widget.
But all of this doesn't matter much, since the WA_ attributes are for widgets, and do nothing for windows. You want something else entirely: to make the window itself transparent for input. Thus, in QML:
window.flags = window.flags | Qt.WindowTransparentForInput
来源：https://stackoverflow.com/questions/52803057/qt-selectively-allow-a-click-to-fall-through-to-a-lower-application-window