C++ 想从基类调用派生函数

Question

我有以下情况

class base
{
public:

   virtual void Accepted(SOCKET s)  //// Event
   {

   }
   void Listner()
   {
          SOCKET acpted;
          Accepted(acpted); /// When I call I want derived class's Accepted() to get called

   }

};


class derived
{
   virtual void Accepted(SOCKET s)  //// Event
   {
         ////// HERE i will write actual implementation (QUESTION)
   }

}

我想调用派生类的函数。这将像这里的事件一样工作。我想通知派生类基类发生了一些事情。

Answer 1

class derived : public base 将使 derived 实际上继承自 base。然后您的虚函数调用将按预期工作。

请注意，您不能在 base 的构造函数或析构函数中调用此类虚函数 - 在调用 base 的构造函数时，derived 部分还不存在。在调用 base 析构函数时，derived 部分已经被析构。

编辑:演示，以回应评论。

class base
{
public:
    virtual void Accepted(SOCKET s)  //// Event
    {
        cout << "base::Accepted" << endl;
    }
    void Listner()
    {
        SOCKET acpted = 0;
        Accepted(acpted); /// When I call I want derived class's Accepted() to get called
    }
};


class derived : public base
{
    virtual void Accepted(SOCKET s)  //// Event
    {
        cout << "derived::Accepted" << endl;
    }
};


int main(int argc, char * argv[])
{
  derived d;
    d.Listner();
}

这将打印derived::Accepted