QT学习之绘图

绘图事件

void Widget::paintEvent(QPaintEvent *event)
{
   
    //实例化画家对象,this是指在当前widget设备上进行画画
    QPainter painter(this);

    //设置画笔, 要先设置画笔才会有显示
    QPen pen(QColor(255,0,0));
    pen.setStyle(Qt::DashLine);
    pen.setWidth(5);

    //让画家使用笔
    painter.setPen(pen);

    //设置画刷
    QBrush brush(QColor(10,2,15));
    brush.setStyle(Qt::VerPattern);//风格
    painter.setBrush(brush);//对封闭图形进行填充上色

    //画一条线
    painter.drawLine(QPoint(0,0),QPoint(100,100));
    //画圆
    painter.drawEllipse(QPoint(100,500),50,50);
    //画矩形
    painter.drawRect(QRect(100,50,20,20));
    //画文字
    painter.drawText(200,200,"你好");


}

高级设置

抗锯齿

    painter.drawEllipse(QPoint(110,110),100,100);
    painter.setRenderHint(QPainter::Antialiasing);//设置抗锯齿能力
    painter.drawEllipse(QPoint(400,110),100,100)