Qt休眠

QTest::qSleep(250); //unresponsive

QTest::qWait(250); //stay responsive

QThread::usleep(100); //milliseconds

QThread::msleep(100); //usecs microseconds 微妙

参考：https://blog.csdn.net/xiezhongyuan07/article/details/81169583

https://www.cnblogs.com/yangjunhe460/p/10289613.html

在主线程中休眠的正确方法：

定时器与QEventLoop配合使用

QEventLoop eventloop;
QTimer::singleShot(5000, &eventloop, SLOT(quit()));
eventloop.exec();