i read about this problem some solution but don't work.

shortly i want to do this;

QPixmap pix;
pix.load(":XXX/Resources/r1.png"); // transparent png file
pix.toWinHBITMAP(QPixmap::PremultipliedAlpha); // but this is not transparent

this is not transparent. it has black background.

if somebody help me or give me a link about that i will be very happy.

thank you...