if hide titlebar, the widget cannot be removed

[kobe]

In Qt4 ,the QDeclarativeView can be loaded by QStackedWidget, then I used SetWindowFlags(), I can hide titlebar and rewrite the mouse events. But in Qt5, the QDeclarativeView has been replaced by QQuickView, I use the setFlags() can hide titlebar, but it cannot be reloaded by any widget, so the rewrited mouse events had no any effect. It leads to that the widget cannot be removed.