C++ member function as a callback - tutorial?

Hi,

this shall be quite easy. Member callback function shall be static and should accept at least one parameter that is the pointer the callback object, which is an instance of the class that has the callback method.

The following class has a callback method _MyCallbackMethod:

class CMyCallbackClass
{
public:
   static void __stdcall _MyCallbackMethod(void* pObject, int iMyParam>)
   {
       CMyCallbackClass* pThis = reinterpret_cast<cmycallbackclass*>(pObject);
       pThis->MyCallbackMethod(iMyParam);
   }   
   
   void MyCallbackMethod(int iMyParam)
   {
       // your code here
   }
};

And finally, you give another object a pointer to the static method _MyCallbackMethod to another class:

class X
{
public:
   void SetCallbackMethod(void (*methoPtr)(int))
   {
      this->m_pPtr = methoPtr;
   }
};

The X class will call the callback in the following way:

this->pPtr(10);

Best regards,
J. K.

Look under the keyword "Delegate". There are several nice articles about this subject here on CodeProject. A delegate is in simple words the combination of a member function pointer and an object pointer. It allows you to call a certain member function of a specific object from just a single entity.

Delegates, when implemented right, are much easier to deal with than the classical C++ member function pointers.