6
考虑这个测试用例:为什么QObject销毁称为AFTER销毁的信号?
class MyObject : public QObject
{
Q_OBJECT
public:
MyObject() { qDebug() << "MyObject constructor"; }
virtual ~MyObject() { qDebug() << "MyObject destructor"; }
};
class Tracker : public QObject
{
Q_OBJECT
public:
Tracker() {}
public slots:
void onDestructor() { qDebug() << "About to be destroyed!"; }
};
int main(int argc, char** argv)
{
QCoreApplication app(argc, argv);
Tracker tracker;
MyObject *obj = new MyObject();
QObject::connect(obj, SIGNAL(destroyed()), &tracker, SLOT(onDestructor()));
delete obj;
return app.exec();
}
它打印这样的:
MyObject constructor
MyObject destructor
About to be destroyed!
此行为违背Qt文档:“,这个信号被立即发出之前obj对象被破坏,并能不被阻止。“这是为什么发生?