在《The book of Qt4》上看到这么一段话：
The call to
exec() starts the event loop which is in charge of forwarding application events to the appropriate objects.Such events are caused by user actions, such as clicking a
button.
The event loop is terminated when the quit() function of the QApplication object is called.
还有这么一句话：Finally we start the event loop
and pass the return code from the event loop back as the application's return value. A simple return 0; would terminate the application immeditately without even display the
window.
比如下面这个例子：
- #include <QApplication>
- #include <QLabel>
- int main(int argc, char *argv[])
- {
- QApplication a(argc, argv);
- QLabel label("Hello World");
- label.show();
-
- return a.exec();
- }
求大家帮忙通过这个小程序解释下循环机制。
是a.exec()开始事件循环吗？那return a.exec()与结束的花括号之间是如何
执行的？
return a.exec()是指a.exec()这个事件循环返回一个值，然后通过return 这个值来结束程序？
