How to change the handle's height of the qsrcollbar ?

[nicker player]

I used the code below.but didnt work.
the handle still higher than 30px. it is related to the qwidget height I ve put. so how to change it?
scrollArea->verticalScrollBar()->setStyleSheet("QScrollBar::handle:vertical{height:30px;}");

[SimonSchroeder]

Try without :vertical. From my understanding :vertical is a pseudo state of QScrollBar and not of its handle. I'm not sure how this would work if you really needed both :vertical and ::handle. But, at least in the example you provided you set the stylesheet on a specific scroll bar. In that case you really don't have to distinguish between vertical and horizontal scroll bars.