Qt：QtPainter设置画笔-蒲公英云

Qt：QtPainter设置画笔

#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();
}

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();
}

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();
}