larger(not to scale) a exist QPixmap and paint more thing on the blank space

[calmspeaker]

QPixmap.transformed(QTransform::fromTranslate(x,y) ) did not have a good result.
Is there a way?

[ChrisW67]

Have you tried QPixmap::scaled(), QPixmap::scaledToWidth() and QPixmap::scaledToHeight() ?

Where do you want to put the larger QPixmap? On a QLabel? Then just have a look at QLabel::scaledContents()

[calmspeaker]

yes,i tried the scaled(), but it did not work as I wanted. It just scaled the whole picture. what i wanted is just larger the paint area and leave the origin picture unchanged.Then I will draw something on the blank area.

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Added after 32 minutes:

Is it a complicated problem?

[meazza]

Well if you just want to adjust the size of the paint area it is not very complicated. Lets say that you are painting in a QWidget then in paintEvent() you can do something like this.

QPixmap example;
    example.load("Picturepath");
    QSize pixmapSize = example.size();
    this->resize(pixmapSize);

QPixmap example;
    example.load("Picturepath");
    QSize pixmapSize = example.size();
    this->resize(pixmapSize);

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Edit: And of course use QPainter::drawPixmap after that

[MrShahi]

Use QPainter inside paint event and draw pixmap through
void QPainter::drawPixmap ( int x, int y, int width, int height, const QPixmap & pixmap )
I hope it will help you...

[calmspeaker]

You did help me！ Thank you.

QPixmap pixicon = item->icon(column).pixmap(QSize(32,32));//the origin icon
			QPixmap pix(32,32);//store the modified icon
			pix.fill(Qt::transparent);
			QPainter paint(&pix);
			paint.drawPixmap(16,16,16,16,pixicon);//bottom right paint pixicon
 
			paint.drawLine(QPointF(12,0),QPointF(12,24));//modify the pixmap
			paint.drawLine(QPointF(0,12),QPointF(24,12));

QPixmap pixicon = item->icon(column).pixmap(QSize(32,32));//the origin icon
			QPixmap pix(32,32);//store the modified icon
			pix.fill(Qt::transparent);
			QPainter paint(&pix);
			paint.drawPixmap(16,16,16,16,pixicon);//bottom right paint pixicon
			
			paint.drawLine(QPointF(12,0),QPointF(12,24));//modify the pixmap
			paint.drawLine(QPointF(0,12),QPointF(24,12));

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