QT自定义控件0-360°刻度尺

支持0到360°，360到0°的过度。
直接上代码，可以直接用，使用的paintevent事件实现的，没啥好讲的。

.cpp

void Widget::drawCourse(QPainter& p,QPen pen,QFont font)
{double currentNumber = m_ang;p.setBrush(Qt::black);p.drawRect(rect());//航向刻度图pen.setColor("#ffffff");pen.setWidth(2);p.setPen(pen);font.setPointSize(20);p.setFont(font);p.drawLine(0,0,width(),0);int mainScale = 360;double movePos = currentNumber*35-width()/2;//360前半截for (int i = 0; i < mainScale+1; ++i) {if (i%5 == 0){pen.setWidth(2);p.setPen(pen);p.drawLine(0+i*35-movePos,0,0+i*35-movePos,26);p.drawText(0+i*35-30-movePos,33,60,30,Qt::AlignCenter,QString::number(i%360));}else{pen.setWidth(1);p.setPen(pen);p.drawLine(0+i*35-movePos,0,0+i*35-movePos,20);}}//0后半截,360前半截double startPt = 0;double showSpan = width()/35.00;if (currentNumber > 360 - showSpan || currentNumber < 360 - showSpan){if (currentNumber > 360 - showSpan)startPt = (360 - currentNumber + showSpan/2)*35;elsestartPt = (showSpan/2 - currentNumber)*35 - 35*mainScale;for (int i = 0; i < mainScale+1; ++i) {if (i%5 == 0){pen.setWidth(2);p.setPen(pen);p.drawLine(0+i*35+startPt,0,0+i*35+startPt,26);p.drawText(0+i*35-30+startPt,33,60,30,Qt::AlignCenter,QString::number(i%360));}else{pen.setWidth(1);p.setPen(pen);p.drawLine(0+i*35+startPt,0,0+i*35+startPt,20);}}}//航向中线p.setPen(QPen(QColor("#009af7")));p.setBrush(QBrush(QColor("#009af7")));QPolygon pol;pol<<QPoint(width()/2,72)<<QPoint(width()/2-17,103)<<QPoint(width()/2+16,103);p.drawPolygon(pol);
}