[Qt-interest] MyQWidget's paintEvent will not be called if ...

[James Yan]

hey all,
  i write a widget public from QWidget to show a picture, so my code looks
like this:

//constructor
ImageWidget::ImageWidget(QWidget *parent,QImage* pImage) : QWidget(parent)
{
    m_pImage = pImage;
    setFixedSize(1,1);      // MUST GIVE A SIZE, OTHERWISE PaintEvent WILL
NOT BE CALLED!
}

//paint event
void ImageWidget::paintEvent(QPaintEvent * /* event */)
{
    //get the painter
    QPainter painter(this);

    //draw the image
    if(m_pImage)
    {
        QImage
img(m_pImage->bits(),m_pImage->width(),m_pImage->height(),m_pImage->format());
        painter.drawImage(QPoint(0,0),img);
        setFixedSize(m_pImage->width(),m_pImage->height());
    }
}

then, i put the widget in a scrollArea of a mainwindow, what a fun that i
found if i did not give the widget a fixed size in it's constructor, then my
picture will not be painted out, in other word, the paintEvent will alwasy
not be called! i do not know why, i think it maybe a bug or something.

thanks.
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