哪个网站做欧洲旅游攻略好,手机网站可以做英文版本吗,苏中建设集团网站官网,深圳网站建设yuntianxia1、设计思想雷达扫描图#xff0c;在影视作品中见到较多#xff0c;比如飞机雷达、舰艇雷达#xff0c;有一个扫描线转圈代表雷达一周旋转或一个批次的收发#xff0c;发现目标就在表盘上标记位置。和汽车仪表盘类似#xff0c;汽车仪表盘有底盘背景图、同圆、刻度、刻度值…1、设计思想雷达扫描图在影视作品中见到较多比如飞机雷达、舰艇雷达有一个扫描线转圈代表雷达一周旋转或一个批次的收发发现目标就在表盘上标记位置。和汽车仪表盘类似汽车仪表盘有底盘背景图、同圆、刻度、刻度值、旋转的指针。能在汽车仪表盘的基础上略作修改比如指针换成带有余辉的扫描扇面就能完成一个雷达扫描图。代码实现原理上图的扫描线和余辉效果可以使用QConicalGradient 函数来实现qconicalgradient()提供的是一种扇形渐变效果圆锥式渐变或称角度渐变。用这个渐变色来填充drawPie函数就可以实现扇形选择的余辉。QConicalGradient::QConicalGradient(qreal cx, qreal cy, qreal angle)void QPainter::drawPie(const QRectF rectangle, int startAngle, int spanAngle)Qt大神刘典武文章中有典型的讲解《Qt编写自定义控件62-探探雷达》中实现的扫描效果就是雷达的效果。详情移步https://zhuanlan.zhihu.com/p/85512788。2、代码实现绘制同心圆x和y轴实线45度对角线虚线。void Radar::drawCircle(QPainter *painter){painter-save();QColor color QColor(0, 100, 0);QPen pen QPen(color, 2);painter-setPen(pen);for(int i0; i4; i){int r this-radius / 4 * (i1);painter-drawEllipse(-r, -r, r * 2, r * 2);}for(int i0; i4; i) // x,y 轴线是实线{int r this-radius;if((i%2) 0) {pen.setStyle(Qt::SolidLine);}else{pen.setStyle(Qt::DashDotLine);//pen.setDashPattern(QVector() 10 2 ); //实线空线的比例}painter-setPen(pen);painter-drawLine(-r, 0, r, 0);painter-rotate(90/2);}painter-restore();}绘制扫描图依靠锥形渐变颜色,通过透明度控制形成扫描效果然后绘制饼图。void Radar::drawScan(QPainter *painter){painter-save();//锥形渐变颜色,通过透明度控制形成扫描效果QConicalGradient conicalGradient(0, 0, this-angle);QColor color QColor(0,150,0);color.setAlpha(100);conicalGradient.setColorAt(0, color);color.setAlpha(20);conicalGradient.setColorAt(0.1, color);color.setAlpha(0);conicalGradient.setColorAt(1, color);//绘制饼圆QPen pen;pen.setWidth(5);pen.setBrush(conicalGradient);painter-setPen(pen);painter-setBrush(conicalGradient);int r this-radius;QRect rect(-r, -r, r * 2, r * 2);painter-drawPie(rect, this-angle * 16, 360 * 16); // 1/16th of a degreepainter-restore();}给雷达加上模拟的扫描目标实现起来很简单就是打点。void Radar::drawPoints(QPainter *painter){painter-save();QColor color QColor(200, 10, 0);QPen pen QPen(color, 1);painter-setPen(pen);painter-setBrush(color);for(int i0; ipoints.count(); i){int r 6;QRect rect(points[i].x() - r/2, points[i].y() - r/2, r * 2, r * 2);painter-drawEllipse(rect);// 画实心小点}painter-restore();}最终效果如下。外层怎么 调用使用信号和槽驱动Radar类对象。RadarScan::RadarScan(QWidget *parent): QMainWindow(parent), ui(new Ui::RadarScan){ui-setupUi(this);// start and stopconnect(this, RadarScan::radar_state_changed,ui-radar, Radar::radar_start_control);connect(ui-startButton, QPushButton::clicked, [](){emit radar_state_changed(true);});connect(ui-stopButton, QPushButton::clicked, [](){emit radar_state_changed(false);});// speed controlconnect(this, RadarScan::radar_speed_changed,ui-radar, Radar::radar_speed_control);connect(ui-fastButton, QPushButton::clicked, [](){emit radar_speed_changed(true);});connect(ui-slowButton, QPushButton::clicked, [](){emit radar_speed_changed(false);});connect(ui-randomButton, QPushButton::clicked, ui-radar, Radar::radar_random_point);}3、效果演示
