QPixmap scaling question

[eric]

Hello.
I create two QPixmaps: one is loaded from a bitmap file, the other one is drawn. The first one can be rescaled with scaled(), the second one can not. Do you know why? Thank you!

This scaling works

QPixmap pm(600,450);
     pm.load("image.jpg");
     pm = pm.scaled(300,225); //this works fine
     pixmapLabel->setPixmap(pm);

QPixmap pm(600,450);
     pm.load("image.jpg");
     pm = pm.scaled(300,225); //this works fine
     pixmapLabel->setPixmap(pm);

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This scaling won't work:

QPixmap pm(600,450);
     QPainter p(&pm);
     QPen pen(Qt::red, 2);
     p.setPen(pen);
     p.drawLine(0, 0, 600, 450);
     pm = pm.scaled(300,225);//this has no effect. why?
     pixmapLabel->setPixmap(pm);

QPixmap pm(600,450);
     QPainter p(&pm);
     QPen pen(Qt::red, 2);
     p.setPen(pen);
     p.drawLine(0, 0, 600, 450);
     pm = pm.scaled(300,225);//this has no effect. why?
     pixmapLabel->setPixmap(pm);

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