qt如何实现一个渐隐窗口呢（开启的时候他是从上往下渐渐显示）

qt如何实现一个渐隐窗口呢？就是比如说开启的时候他是从上往下渐渐显示的，关闭的时候从下往上渐渐小时的
http://stackoverflow.com/questions/19087822/how-to-make-qt-widgets-fade-in-or-fade-out

 

Fade In Your Widget

// w is your widget QGraphicsOpacityEffect *eff = new QGraphicsOpacityEffect(this); w->setGraphicsEffect(eff); QPropertyAnimation *a = new QPropertyAnimation(eff,"opacity"); a->setDuration(350); a->setStartValue(0); a->setEndValue(1); a->setEasingCurve(QEasingCurve::InBack); a->start(QPropertyAnimation::DeleteWhenStopped);

Fade Out Your Widget

// w is your widget QGraphicsOpacityEffect *eff = new QGraphicsOpacityEffect(this); w->setGraphicsEffect(eff); QPropertyAnimation *a = new QPropertyAnimation(eff,"opacity"); a->setDuration(350); a->setStartValue(1); a->setEndValue(0); a->setEasingCurve(QEasingCurve::OutBack); a->start(QPropertyAnimation::DeleteWhenStopped); connect(a,SIGNAL(finished()),this,SLOT(hideThisWidget())); // now implement a slot called hideThisWidget() to do // things like hide any background dimmer, etc.