QGraphicsView上加载图片如何跟随鼠标滚轮缩放,附上代码
QGraphicsView上加载图片如何跟随鼠标滚轮缩放
void LABcolony_selection::slot_zoomfunction(bool zoom)
{
QMatrix matrix;
if(zoom && m_zoom_level <= 250)
{
m_zoom_level += 5;
qDebug() << m_zoom_level;
qreal scale = qPow(qreal(2), (m_zoom_level - 250) / qreal(50));
qDebug() << scale;
matrix.scale(0.8+scale, 0.8+ scale);
ui->graphicsView->setMatrix(matrix);
}
else if(!zoom && m_zoom_level > 1)
{
m_zoom_level -= 5;
qDebug() << m_zoom_level;
qreal scale = qPow(qreal(2), (m_zoom_level - 250) / qreal(50));
matrix.scale(0.8+scale, 0.8+scale);
ui->graphicsView->setMatrix(matrix);
}
else if (!zoom && m_zoom_level == 1)
{
matrix.scale(0.8, 0.8);
ui->graphicsView->setMatrix(matrix);
}
return;
}
我这里虽然可以缩放,但是无法跟随鼠标,请指教