QPainter出现错误，程序退出

#include <QImage>
#include <QPainter>

int main()
{
        QImage img(400, 300, QImage::Format_RGB32);
        img.fill(0);

        QPainter pain;
        pain.begin(&img);

        pain.drawText(10,10, "abc");

        pain.end();

        img.save("./ttt.jpg");

        return 0;
}