延迟启动 QPropertyAnimation

Question

我有一个小动画 showing/hiding 当鼠标悬停在父窗口小部件上时的一个帧（在下面的代码片段中 "MyWidget"）。

动画只是改变了框架的最大宽度属性，因此框架变得可见 "slide-in effect"。（框架本身放置在网格布局中。）

我的问题是如何延迟启动动画？示例：在鼠标离开事件后500ms开始，所以滑出效果是延迟的，没有立即开始。

void MyWidget::enterEvent( QEvent * event )
{
    //slide-in effect
    QPropertyAnimation *animation = new QPropertyAnimation(ui.frame_buttons, "maximumWidth");
    animation->setDuration(1000);
    animation->setStartValue(ui.frame_buttons->maximumWidth());
    animation->setEndValue(100);
    animation->setEasingCurve(QEasingCurve::InOutQuad);

    animation->start();
}

void MyWidget::leaveEvent( QEvent * event )
{
    //slide-out effect
    QPropertyAnimation *animation = new QPropertyAnimation(ui.frame_buttons, "maximumWidth");
    animation->setDuration(1000);
    animation->setStartValue( ui.frame_buttons->maximumWidth() );
    animation->setEndValue(0);
    animation->setEasingCurve(QEasingCurve::InOutQuad);

    //delay start() for a small amount of time
    animation->start();
}

Answer 1

Mezzo 的提示是针对目标 - 再次感谢！ - 但我插入了一个检查器以避免 'flicker effect'。 （当 slideIn 效果仍为运行时，始终等待静态的毫秒数会导致异步 slideOut 效果。）

可能对答案感兴趣的人。（我还修复了避免在每个动画触发器中分配的内存泄漏）：

void MyWidget::enterEvent( QEvent * event )
{
    //start from where the slideOut animation currently is
    m_slideInAnimation->setStartValue(ui.frame_buttons->maximumWidth());
    m_slideInAnimation->start();
}

void MyWidget::leaveEvent( QEvent * event )
{
    //start from where the slideIn animation currently is
    m_slideOutAnimation->setStartValue( ui.frame_buttons->maximumWidth() );

    //start slide_out animation only if slide_in animation finish to avoid flicker effect
    if(ui.frame_buttons->maximumWidth() != m_slideInAnimation->endValue()) 
    {
        m_slideOutAnimation->start();
    }
    else
    {
        QTimer::singleShot(700, m_slideOutAnimation, SLOT(start()));
    }   
}

void MyWidget::createAnimations()
{
    m_slideInAnimation= new QPropertyAnimation(ui.frame_buttons, "maximumWidth");
    m_slideInAnimation->setDuration(1000);
    m_slideInAnimation->setEndValue(100);
    m_slideInAnimation->setEasingCurve(QEasingCurve::InOutQuad);

    m_slideOutAnimation = new QPropertyAnimation(ui.frame_buttons, "maximumWidth");
    m_slideOutAnimation->setDuration(1000);
    m_slideOutAnimation->setEndValue(0);
    m_slideOutAnimation->setEasingCurve(QEasingCurve::InOutQuad);
}

void MyWidget::MyWidget()
{
    this->createAnimations();
}

void MyWidget::~MyWidget()
{
    delete m_slideInAnimation;
    delete m_slideOutAnimation;
}

延迟启动 QPropertyAnimation

Start QPropertyAnimation delayed

qt

qt4

qpropertyanimation