在Qt中如何使用QPainter进行画图 基础功能实现

现在头文件中增加重载

#include <QPaintEvent>

protected:
void paintEvent(QPaintEvent *event);

然后在CPP中实现该函数即可。

void TestPainter::paintEvent(QPaintEvent *event)//每个类的药实现的绘制图形都可以在这里实现。

{
QPainter painter(this);
painter.setRenderHints(QPainter::Antialiasing| QPainter::TextAntialiasing);
painter.begin(this);
QPixmap a;
a.load("./10010.jpg");
QPointF p(30,30);
QRectF b(0,0,180,224);
painter.drawImage(b,a.toImage(),a.rect());
// a.save("ok.jpg");
painter.drawRect(b.toRect());
painter.end();

}

QPainter painter(this);
painter.setRenderHints(QPainter::Antialiasing| QPainter::TextAntialiasing);
painter.begin(this);
QPixmap a;
a.load("./10010.jpg");
QPointF p(30,30);
QRectF b(0,0,180,224);
painter.drawImage(b,a.toImage(),a.rect());
// a.save("ok.jpg");
painter.setPen(QColor(0,0,0));
painter.drawEllipse(QPoint(50,50),40,40);




painter.end();