Qt把double类型的时间转化为QDateTime类型

QDateTime *dt=new QDateTime;
    int day =dTime/1;
    int secs =(dTime-day)*24*60*60/1;
    int msecs =((dTime-day)*24*60*60-secs)*1000;
    dt->setDate(QDate(1899,12,30));
    dt->setTime(QTime(0,0,0,0));
    *dt = dt->addDays(day);
    *dt = dt-> addSecs(secs);
    msecs=dTime*24*60*60*1000;
    *dt = dt->addMSecs(msecs);
    *str=dt->toString("yyyy-MM-dd hh:mm:ss");