1：

void QTimer::singleShot ( int msec, QObject * receiver, const char * member ) [static]   

样例：
 #include <QApplication>
 #include <QTimer>
 int main(int argc, char *argv[])
 {
  QApplication app(argc, argv);
  QTimer::singleShot(600000, &app, SLOT(quit()));
  ...
  return app.exec();
 }

2：

    QTime n=QTime::currentTime();
    QTime now;
    do{
          qDebug()<<"jjmm";
          now=QTime::currentTime();
     }   while (n.msecsTo(now)<=1);

 

3：

QDateTime n2=QDateTime::currentDateTime();
  QDateTime now;
  do{
  now=QDateTime::currentDateTime();
  } while (n2.secsTo(now)<=6);//6为需要延时的秒数