c++ - 如何在退出时调用插槽

Question

我想在我的 Qt 应用程序关闭之前更新我的数据库。

我想要类似connect(this, SIGNAL(quit()), this, SLOT(updateDatabase()))一种方法是引入一个退出按钮，但是如果用户按下 Alt+F4 是否可以实现此功能？

Answer 1

使用信号aboutToQuit()相反。

This signal is emitted when the application is about to quit the main event loop, e.g. when the event loop level drops to zero. This may happen either after a call to quit() from inside the application or when the users shuts down the entire desktop session.

The signal is particularly useful if your application has to do some last-second cleanup. Note that no user interaction is possible in this state.

例如:

connect(this, SIGNAL(aboutToQuit()), this, SLOT(updateDatabase()));