[Qt-interest] How can I make a pushbutton be transparent?

[Kermit Mei]

Hello,comminity!

I want to make some Widgets be transparent, but I don't know how to do
it highly efficient. I want to run my program on ARM, and there may be
many widgets.

Except to make some Widget be transparent, I also need to add some
back-ground pictures on them.
If I setStyleSheet, will it make my program slowly? And how to write a
transparent widget's style sheet?

Is subclassing QStyle a better way to use style sheet to promote the
efficience? Or other better ways?

Thanks.

Kermit