问题解决:
void MyGLWidget::paintGL()
{
......
QFont font("Times", 30, QFont::Bold);
QPainter painter(this);
int x = 100;
draw(&painter,30,x,80,"first",font);
x+=150;
draw(&painter,30,x,80,"first",font);
x+=150;
draw(&painter,30,x,80,"first",font);
painter.end();
}
void MyGLWidget::draw( QPainter *painter,double angle, double x, double y, const QString &str, const QFont &font)
{
painter->setPen(Qt::white);
painter->setFont(font);
painter->save();
painter->translate(x, y);
painter->rotate(angle);
painter->drawText(0,0, str);
painter->restore();
}