Qt：QtPainter设置画笔

逃离我推掉我的手 2022-10-24 11:46 266阅读 0赞

#include <QPainter>
    #include <QFont>
    void MainWindow::paintEvent(QPaintEvent *)
    {
        QPainter painter;
        painter.begin(this);
    
        QPen pen(Qt::black);
        pen.setStyle(Qt::SolidLine);
        pen.setWidth(20);
    
        QPointF p1[3] = {
            QPointF(30.0, 80.0),QPointF(20.0, 40.0), QPointF(80.0, 60.0)
        };
        QPointF p2[3] = {
            QPointF(130.0, 80.0), QPointF(120.0, 40.0), QPointF(180.0, 60.0)
        };
        QPointF p3[3] = {
            QPointF(230.0, 80.0), QPointF(220.0, 40.0), QPointF(280.0, 60.0)
        };
    
        pen.setJoinStyle(Qt::MiterJoin);
        painter.setPen(pen);
        painter.drawPolyline(p1, 3);
    
        pen.setJoinStyle(Qt::BevelJoin);
        painter.setPen(pen);
        painter.drawPolyline(p2, 3);
    
        pen.setJoinStyle(Qt::RoundJoin);
        painter.setPen(pen);
        painter.drawPolyline(p3, 3);
    
        painter.end();
    }

![8d2bc65ac0164a48a7b132bd3175d26e411.jpg][]

画笔的连接风格

#include <QPainter>
    #include <QFont>
    void MainWindow::paintEvent(QPaintEvent *)
    {
        QPainter painter;
        painter.begin(this);
    
    
        QPen pen(Qt::black);
        pen.setStyle(Qt::SolidLine);
        pen.setWidth(20);
    
            pen.setCapStyle(Qt::FlatCap);
            painter.setPen(pen);
            painter.drawLine(30, 30, 200, 30);
    
            pen.setCapStyle(Qt::SquareCap);
            painter.setPen(pen);
            painter.drawLine(30, 70, 200, 70);
    
            pen.setCapStyle(Qt::RoundCap);
            painter.setPen(pen);
            painter.drawLine(30, 110, 200, 110);
    
        painter.end();
    }

![6deff8ab4e913c5b4f28ff7f45ceb6f6b53.jpg][]

画笔的三种边角。

void MainWindow::paintEvent(QPaintEvent *)
    {
        QPainter painter;
        painter.begin(this);
    
        QRect rect1(10.0, 20.0, 80.0, 50);
        QRect rect2(110.0, 20.0, 80.0, 50.0);
        QRect rect3(210.0, 20.0, 80.0, 50.0);
        QRect rect4(10.0, 100.0, 80.0, 50.0);
        QRect rect5(110.0, 100.0, 80.0, 50.0);
        QRect rect6(210.0, 100.0, 80.0, 50.0);
    
            QPen pen(Qt::blue, 3, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin);
            painter.setPen(pen);
            painter.drawEllipse(rect1);  //画椭圆
    
            pen.setStyle(Qt::DashLine);
            painter.setPen(pen);
            painter.drawEllipse(rect2);
    
            pen.setStyle(Qt::DotLine);
            painter.setPen(pen);
    
            painter.drawEllipse(rect3);
    
            pen.setStyle(Qt::DashDotLine);
            painter.setPen(pen);
    
            painter.drawEllipse(rect4);
    
            pen.setStyle(Qt::DashDotDotLine);
            painter.setPen(pen);
            painter.drawEllipse(rect5);
    
            pen.setStyle(Qt::CustomDashLine);
            painter.setPen(pen);
            painter.drawEllipse(rect6);
        painter.end();
    }

![045ea8dc64d0c145fadc0bde52fb70b238c.jpg][]

设置画笔的轮廓

\--

[8d2bc65ac0164a48a7b132bd3175d26e411.jpg]: /images/20221024/8b7bcf2125e34655bd0ccbfb96107f8e.png
[6deff8ab4e913c5b4f28ff7f45ceb6f6b53.jpg]: /images/20221024/ce68eee09c344de399a01346d55296ae.png
[045ea8dc64d0c145fadc0bde52fb70b238c.jpg]: /images/20221024/b44209809ad4445bba11be4a696baf8f.png