QT5 雷达扫描效果代码

#include "cradar.h" #include <QPainter> #include <QTimerEvent> #include <QConicalGradient> #include <qDebug> #include<math.h> CRadar::CRadar(QWidget *parent) : QWidget(parent) { //初始化 m_pieRotate = 0; m_timerId = -1; m_nSpeed = 50; m_points<<QPoint()<<QPoint()<<QPoint()<<QPoint()<<QPoint(); m_pointsAlapha<<100<<100<<100<<100<<100; //启动定时器 m_timerId = startTimer(m_nSpeed); m_pointTimerId = startTimer(1200); } void CRadar::paintEvent(QPaintEvent *event) { QPainter painter(this); //抗锯齿 painter.setRenderHint(QPainter::Antialiasing); //背景 painter.fillRect(rect(),QColor(100,100,200)); //边长 int len = m_drawArea.width(); //底盘(x轴、y轴和3个圆) painter.setPen(QPen(Qt::white)); painter.drawLine(m_drawArea.topLeft() + QPoint(0,len/2),m_drawArea.topRight() + QPoint(0,len/2)); painter.drawLine(m_drawArea.topLeft() + QPoint(len/2,0),m_drawArea.bottomLeft() + QPoint(len/2,0)); painter.drawEllipse(m_drawArea.center(),len/2,len/2); painter.drawEllipse(m_drawArea.center(),len/3,len/3); painter.drawEllipse(m_drawArea.center(),len/6,len/6); //转动部分 //---//线 qreal x = m_drawArea.center().x() + (qreal)len/2 * cos(-m_pieRotate*3.14159/180); qreal y = m_drawArea.center().y() + (qreal)len/2 * sin(-m_pieRotate*3.14159/180); painter.setPen(QPen(Qt::white)); painter.drawLine(m_drawArea.center(),QPointF(x,y)); //----//扇形 QConicalGradient gradient; gradient.setCenter(m_drawArea.center()); gradient.setAngle(m_pieRotate + 180); //渐变与旋转方向恰好相反，以扇形相反的边作为渐变角度。 gradient.setColorAt(0.4,QColor(255,255,255,100)); //从渐变角度开始0.5 - 0.75为扇形区域，由于Int类型计算不精确，将范围扩大到0.4-0.8 gradient.setColorAt(0.8,QColor(255,255,255,0)); painter.setBrush(QBrush(gradient)); painter.setPen(Qt::NoPen); painter.drawPie(m_drawArea,m_pieRotate*16,90*16); //装饰-随机点 for(int i = 0; i < m_points.count(); ++i) { int colorAlaph = m_pointsAlapha.at(i); painter.setPen(QPen(QColor(255,255,255,colorAlaph),3)); painter.drawPoint(m_points.at(i)); } //更详细解释参考：http://fearlazy.com/index.php/post/31.html } void CRadar::resizeEvent(QResizeEvent *event) { //以较短的边长作为绘制区域边长 if(width() > height()) { m_drawArea = QRect((width() - height())/2,0,height(),height()); } else { m_drawArea = QRect(0,(height() - width())/2,width(),width()); } m_drawArea.adjust(10,10,-10,-10); } void CRadar::timerEvent(QTimerEvent *event) { if(m_timerId == event->timerId()) { m_pieRotate -= 10; update(); } else if(m_pointTimerId == event->timerId()) { //随机更换装饰的点 for(int i = 0; i < m_points.count(); ++i) { int offsetX = rand()%m_drawArea.width(); int offsetY = rand()%m_drawArea.width(); int alapha = rand()%255; m_points.replace(i,QPoint(offsetX,offsetY) + m_drawArea.topLeft()); m_pointsAlapha.replace(i,alapha); } update(); } }