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：
QWaitCondition waitCond;
waitCond.wait (400); // or any other time in [ms]
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
http://blog.csdn.net/liuguangzhou123/article/details/7399253