Qt之QtPainter：設置畫筆[Qt5開發實戰]

#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();
}

畫筆的鏈接風格

#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();
}

畫筆的三種邊角。

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);  //畫橢圓

        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();
}

設置畫筆的輪廓

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