如何从父母 class 呼叫孩子 function

Question

For example i have

class A
{
  void Afunction();
};

and i have

#include "A.h"
class B: public A
{
   void Function();
   
};

    #include "B.h"
    class C
    {
       void UpdateStuff();
       void CreateStuff();
       B* Stuff;
    }

I need call CreateStuff(); from Afunction(); but I can't just #include "Ch" Is there another way to do this?

Answer 1

You can call child function using a pointer or a reference of Parent class that points or references the child object. For example:

#include <iostream>
struct A
{
   virtual void Function()                            //Defination
   { std::cout << "Super_class: A\n"; }
   virtual ~A() {}
};

struct B
{
   virtual void Function() { std::cout << "Child_class\n"; }
};

int main()
{
 A *obj1 = new B;
 obj1->Function();
 B obj2;
 obj2.A::Function();      //Calling to Parent class function(A)
 obj2.Function();         //Calling to Child class function(B)
}

Answer 2

You're unable to achieve that with your current code design. Class A does not inherit from Class C and Afunction() doesn't get passed a reference to Class C.

You can either make A inherit C like you have with B inheriting A or you can pass a reference to the function like so

class A
{
  void Afunction(C* CObject);
};

Furthermore you also can't call child class functions from parent class functions when talking about inheritance. Inheritance works from Top down not from the bottom up.

For example

class A
{
    void Afunction();
};

class B : public A
{
    void Afunction()
    {
        A::Afunction(); // This is valid
    }
}

This is not valid code.

class A
{
    void Afunction()
    {
        B::Afunction(); // This is not valid as A::Afunction() does not inherit from B::Afunction() 
    }

};

class B : public A
{
    void Afunction();
}