问:为什么要把父类的析构函数定义成虚函数?
答:否则子类的析构函数可以未被调用,具体代码如下:
class A
{
public:
A(){TRACE("A()/n");};
~A(){TRACE("~A()/n");};
};class B : public A
{
public:
B(){TRACE("B()/n");};
~B(){TRACE("~B()/n");};
};void CEgDlg::OnButton1()
{
A * p = (A*)new B() ;
delete p ;
}
运行结果如下:
A()
B()
~A()
