现象描述
以下情况中默认是false,设置了SetVsible后仍为false,这是什么原因
QPushButton *btn = new QPushButton(this);
qWarning()<<"isVisible="<<btn->isVisible();//false
btn->setVisible(true);
qWarning()<<"isVisible="<<btn->isVisible();//false
官网文档研究
This property holds whether the widget is visible Calling setVisible(true) or show() sets the widget to visible status if all its parent widgets up to the window are visible. If an ancestor is not visible, the widget won't become visible until all its ancestors are shown. If its size or position has changed, Qt guarantees that a widget gets move and resize events just befor