qpainter设置颜色的几种方式,给矩形框填充颜色，填充圆颜色 去掉边框，qt画弧线

//1
    	QPainter painter(this);
        QColor color;
        color.setRgb(85,0,127);
        painter.setPen(color);
//2
        QPen pen(QColor(124, 122, 121,200));
        pen.setWidth(4);
        painter.setPen(pen);
//3      
        pen.setColor("orange");
        pen.setWidth(4);
        painter.setPen(pen);
//4
        painter.setPen(QColor("#1E90FF"));

//给矩形框填充颜色
        QRect r2(ppos, QSize(200, 220));
        painter.fillRect(r2,QColor(203,203,203,50));
//填充圆颜色
        painter.setBrush(QBrush(QColor(249, 109, 59)));
        painter.setPen(Qt::NoPen);//设置是否有边框
        painter.drawEllipse(c,14,14);
//画弧线
        painter.setPen(pen);
        painter.setRenderHint(QPainter::Antialiasing, true);
        painter.drawArc(rectangle, 0, -180 * 16);//三点钟方向为0
        //冲rectangle里面内切椭圆 从0开始 取-180度  通过调整rectangle的长宽改变弧度大小