Qt :非window子窗体的透明度设置
✿问题的由来
心血来潮,想利用QTimer 配合 setWindowOpacity()方法来实现一个窗体淡入的效果。
✿实验代码
粗糙的实验代码:
- void Widget::on_pushButton_clicked()
- {
- QTimer *timerOpacity = new QTimer(this);
- connect(timerOpacity,SIGNAL(timeout()),this,SLOT(changeOpacity()));
- timerOpacity->start(100);
- }
- void Widget::changeOpacity()
- {
- if (opalevel > 8) return;
- double opacity[9] = {0.9,0.8,0.7,0.6,0.5,0.4,0.3,0.2,0.1};
- ui->stackedWidget->setWindowOpacity(opacity[opalevel]);
- ui->widget->setWindowOpacity(opacity[opalevel]);
- this->setWindowOpacity(opacity[opalevel]);
- qDebug()<<"opalevel = "<< opalevel <<" ui->widget opacity:"<<ui->widget->windowOpacity();
- qDebug()<<"opalevel = "<< opalevel <<" ui->stackedWidget opacity:"<<ui->stackedWidget->windowOpacity();
- qDebug()<<"opalevel = "<< opalevel <<" ui opacity : "<< this->windowOpacity()<<endl;
- }
✿实验失败
现象是主窗体的有淡入的效果,即透明度有变化,但是子窗体没有,opacity始终为1 。
Log :
opalevel = 0 ui->widget opacity: 1
opalevel = 0 ui->stackedWidget opacity: 1
opalevel = 0 ui opacity 0.898039
......
opalevel = 8 ui->widget opacity: 1
opalevel = 8 ui->stackedWidget opacity: 1
opalevel = 8 ui opacity 0.0980392
opalevel = 0 ui->stackedWidget opacity: 1
opalevel = 0 ui opacity 0.898039
......
opalevel = 8 ui->widget opacity: 1
opalevel = 8 ui->stackedWidget opacity: 1
opalevel = 8 ui opacity 0.0980392
✿失败原因
- void QWidget::setWindowOpacity(qreal opacity)
- {
- Q_D(QWidget);
- if (!isWindow())
- return;
- //...
- }
✿解决方案
- // in the constructor
- opacityEffect = new QGraphicsOpacityEffect;
- ui->widget->setGraphicsEffect(opacityEffect);
- ...
- // in changeOpacity()
- opacityEffect->setOpacity(opacity[opalevel]);
✿效果图
![](http://hi.csdn.net/attachment/201109/15/6157840_1316107114d55K.gif)
http://blog.csdn.net/yiyaaixuexi/article/details/6780551