qt函数绘制器的具体代码

以下是一个使用Qt绘制器绘制简单图形的示例代码：

#include <QPainter>
#include <QPen>
#include <QBrush>
#include <QColor>
#include <QPixmap>
#include <QWidget>

class MyWidget : public QWidget
{
public:
    MyWidget(QWidget *parent = nullptr) : QWidget(parent) {}

protected:
    void paintEvent(QPaintEvent *event) override
    {
        QPainter painter(this);
        painter.setRenderHint(QPainter::Antialiasing); // 抗锯齿

        // 绘制直线
        QPen linePen(Qt::red, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin);
        painter.setPen(linePen);
        painter.drawLine(50, 50, 200, 50);

        // 绘制矩形
        QPen rectPen(Qt::blue, 2, Qt::DashLine, Qt::RoundCap, Qt::RoundJoin);
        painter.setPen(rectPen);
        QBrush rectBrush(QColor(255, 0, 0, 127), Qt::DiagCrossPattern);
        painter.setBrush(rectBrush);
        painter.drawRect(50, 100, 150, 100);

        // 绘制椭圆
        QPen ellipsePen(Qt::green, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin);
        painter.setPen(ellipsePen);
        QBrush ellipseBrush(QColor(0, 255, 0, 127), Qt::SolidPattern);
        painter.setBrush(ellipseBrush);
        painter.drawEllipse(50, 250, 150, 100);

        // 绘制多边形
        QPen polygonPen(Qt::black, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin);
        painter.setPen(polygonPen);
        QBrush polygonBrush(QColor(0, 0, 255, 127), Qt::SolidPattern);
        painter.setBrush(polygonBrush);
        QPointF points[4] = {QPointF(300, 50), QPointF(350, 150), QPointF(400, 100), QPointF(350, 50)};
        painter.drawPolygon(points, 4);

        // 绘制圆弧
        QPen arcPen(Qt::magenta, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin);
        painter.setPen(arcPen);
        QBrush arcBrush(QColor(255, 255, 0, 127), Qt::SolidPattern);
        painter.setBrush(arcBrush);
        painter.drawArc(300, 200, 100, 100, 30 * 16, 120 * 16);

        // 绘制图像
        QPixmap pixmap(":/images/qt-logo.png");
        painter.drawPixmap(300, 350, pixmap);
    }
};

在上面的代码中，我们继承了QWidget类，并重写了它的paintEvent函数。在paintEvent函数中，我们首先创建了一个QPainter对象，并设置了一些绘图属性，例如抗锯齿、线条样式、填充样式等等。之后，我们使用QPainter的绘图函数绘制了直线、矩形、椭圆、多边形和圆弧。最后，我们还绘制了一个图像。