Qt时分秒倒计时

QString ExaminationWidget::secsToTime(int s)
{
    int h=0,m=0;
    h=s/3600;
    s%=3600;
    m=s/60;
    s%=60;
    qDebug()<<"m"<<m;
    QString str=QString::number(h)+"时:"+QString::number(m)+"分:"+QString::number(s)+"秒";
    return str;
}