how to use other projects own global variable or static member variable in MFC?

Question

sorry that my english skill is baddest.

when i use c# , i dont't crazy global variable ( no problems used otehr projects static variable in member but when use static variable in MFC ,

i have a problem neither global variabel or static member variable problem too , it's LNK2019 and LNK2001 unreserved external symbols error .

when i use static variable i have declared of members

• .h Source *

  #pragma once
  #include "../CUstomCtl/CUstomCtlDlg.h"
  
  extern CCUstomCtlDlg CusDlg; // this declaration is  when i use for 
                               // global variable
  class CGlobalClass
  {
   public:
   CGlobalClass(void);
  
  ~CGlobalClass(void);
  
   //static CCUstomCtlDlg CusDlg;  // i want CusDlg use to other project 
                                   // like static varialble
  };
  

• .cpp Source *

     #pragma once
     #include "StdAfx.h"
     #include "GlobalClass.h"
     #include "../CUstomCtl/CUstomCtlDlg.h" // CCUstomCtlDlg included
  
  
    CCUstomCtlDlg CusDlg = NULL; // declared like this
  
    CGlobalClass::CGlobalClass(void)
    {
    }
  
  
    CGlobalClass::~CGlobalClass(void)
    {
    }
  

  // i use in other project global variable like this

     #include "../MyGlobal/GlobalClass.h" // i had a include
  
    void CtestDlg::OnBnClickedButton1()
    {
       // TODO: 여기에 컨트롤 알림 처리기 코드를 추가합니다.
  
       CusDlg.DoModal(); // LNK error !! crazyed me .
    }
  

• i want know Two case in MFC *

1. using in global variable to other project not own project
2. using in static member variable to other project not own project

please help me my head will be explosion soon .

Answer 1

This is how to do a global variable

.h source

extern CCUstomCtlDlg CusDlg;

.cpp source

CCUstomCtlDlg CusDlg;

This is how to do a static class variable

.h source

class CGlobalClass
{
    static CCUstomCtlDlg CusDlg;
};

.cpp source

CCUstomCtlDlg CGlobalClass::CusDlg;