cegui事件订阅为什么可以是私有的...

用了很久，也私有了很久～好像以前也想到过～

mLoginBtn->subscribeEvent( CEGUI::Window::EventMouseClick, CEGUI::Event::Subscriber( &GuiLogin::handleClickBtnLogin, this ) );

 

handleClickBtnLogin是私有的函数，Subscriber将函数指针的地址和this对象指针保存起来了。。

为啥不报访问私有函数的错误那？

 

//

//privateMemberFuncPtr.h

 

#pragma once

#include "stdio.h"

class SlotFunctorBase
{
public:
 virtual ~SlotFunctorBase() {};
 virtual void operator()() = 0;
};

SlotFunctorBase* g_SlotFunctorBase;

template<typename T>
class MemberFunctionSlot : public SlotFunctorBase
{
public:
 //! Member function slot type.
 typedef void(T::*MemberFunctionType)();

 MemberFunctionSlot(MemberFunctionType func, T* obj) :
 d_function(func),
  d_object(obj)
 {}

 virtual void operator()()
 {
  return (d_object->*d_function)();
 }

private:
 MemberFunctionType d_function;
 T* d_object;
};

class PrivateMemberFuncPtr
{
public:
 void bind();
private:
 void print()
 {
  printf("success/n");
 }
};

 

//

//privateMemberFuncPtr.cpp

 

#include "PrivateMemberFuncPtr.h"

void PrivateMemberFuncPtr::bind()
{
 g_SlotFunctorBase = new MemberFunctionSlot<PrivateMemberFuncPtr>(&PrivateMemberFuncPtr::print, this);
}

void main()
{
 PrivateMemberFuncPtr* privateMemberFuncPtr = new PrivateMemberFuncPtr;
 privateMemberFuncPtr->bind();
 g_SlotFunctorBase->operator ()();
}

 

 

1.main中生成

privateMemberFuncPtr 0x003d3518

 

2.void PrivateMemberFuncPtr::bind()函数中

0x00411580 PrivateMemberFuncPtr::print(void)

 

3.跟到MemberFunctionSlot的构造函数中

 MemberFunctionSlot(MemberFunctionType func, T* obj) :
 d_function(func),
  d_object(obj)

 

func = 0x00411131 PrivateMemberFuncPtr::print(void)

obj = 0x003d3518

为什么会有差异那？估计在

 virtual void MemberFunctionSlot：：operator()()
 {
  return (d_object->*d_function)();
 }

中可以间接访问私有函数的关键就在上面黄色函数地址发生了变化～希望高手能解答下～