直接上code
void paintEvent(QPaintEvent *event)
{
Q_UNUSED(event);
QPainter painter(this);
QRect rect0 = QRect(0,0,500,500);
painter.drawRect(rect0);
QRect rectB = QRect(-1,-1,501,501);
painter.drawRect(rectB);
//画三角形
QLine line1 = QLine(QPoint(250.0f,80.0f),QPoint(400.0f,350.0f));
QLine line2 = QLine(QPoint(250.0f,80.0f),QPoint(100.0f,350.0f));
QLine line3 = QLine(QPoint(100.0f,350.0f),QPoint(400.0f,350.0f));
painter.drawLine(line1);
painter.drawLine(line2);
painter.drawLine(line3);
painter.drawText(245,75,"PD");
//画刻度
QLine Graduation1_1 = QLine(QPoint(115.0f,324.0f),QPoint(125.0f,324.0f));
QLine Graduation1_2 = QLine(QPoint(129.0f,297.0f),QPoint(139.0f,297.0f));
QLine Graduation1_3 = QLine(QPoint(145.0f,270.0f),QPoint(155.0f,270.0f));
QLine Graduation1_4 = QLine(158.0f,243.0f,168.0f,243.0f);
QLine Graduation1_5