qt中的drawline函数怎的把线加粗

    QPainter painter(this);
    QLineF line(10.0, 80.0, 90.0, 20.0);
    painter.setPen(QPen(Qt::blue, 2/*this param Sets the pen width to the given width in pixels with integer precision.*/));
    painter.drawLine(line);

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C/C++ code

painter->setPen(QPen(QBrush(Qt::darkGray), 2, Qt::SolidLine));
//其中的第2个参数 2 对应线宽

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Qpen里的setWidth函数。

void QPen::setWidth ( int width )
Sets the pen width to the given width in pixels with integer precision.
A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the transformation set on the painter.
Setting a pen width with a negative value is not supported.