Re: How to access Globle veriable from Class function

From:
"Amrit" <cadd@wlink.com.np>
Newsgroups:
microsoft.public.vc.mfc
Date:
Wed, 8 Oct 2008 23:02:03 +0545
Message-ID:
<OpJTomWKJHA.5336@TK2MSFTNGP05.phx.gbl>
Hi Giovanni

it Compile But it does not execute. and when i debug it stop in GetClsB()

This is my code

// from class1
void CClsSheet::Init (const _Sheet *St)
{
 St = new _Sheet; // _Sheet is typedef struct
  HWND pWnd;
 pWnd = GetClsDoc()->CurVar->hWnd ; // it stop here
 St->dc->Init (pWnd );
}

// from Class2

typedef struct tag_Veriable
{
 _Sheet *Sheet;
 HWND hWnd;
 HDC hDC;
 COLORREF Color;

}Veriable;

class Cls_Document
{
public:
 void Init();
 Cls_Document();
 virtual ~Cls_Document();

 void Open();
 void New();
 void Close();
 void SethWnd(HWND hWnd);

 CClsSheet *Sheet;
 Veriable *CurVar, *DefVar; // Current Veriable and Default veriable

};

// Common.h///================================
#if _MSC_VER > 1000
#pragma once
#include "resource.h"
#endif // _MSC_VER > 1000
#include "Test_Document.h"

class Cls_Document;
Cls_Document * GetClsDoc();
// End Common.h///================================

/// Test.Cpp
//==================================

LRESULT CALLBACK About(HWND, UINT, WPARAM, LPARAM);.....

bool InitDocument;
Cls_Document ClsDoc; // this is global veriable
Cls_Document * GetClsDoc()
 {
     return &ClsDoc;
 };

int APIENTRY WinMain(HINSTANCE hInstance,.....

//========================================

"Giovanni Dicanio" <giovanniDOTdicanio@REMOVEMEgmail.com> wrote in message
news:uJ72WDLKJHA.3644@TK2MSFTNGP05.phx.gbl...

"Amrit" <cadd@wlink.com.np> ha scritto nel messaggio
news:uxL$B2KKJHA.728@TK2MSFTNGP03.phx.gbl...

i have one small proble. i need to access Globle veriable from Class
function.


I understand that you would like to access a global variable from a method
defined in a class, is that correct?

typedef Struct Sheet
{

}_Sheet;


I assume that "Struct" is actually "struct" keyword (C++ is case
sensitive, unlike VB, so Struct != struct).
If you don't want back-compatibility with C, I would get rid of the
typedef, it is useless in that scenario for C++ :

struct Sheet
{

   ...
};

works just fine for C++.

// Now in Test.Cpp Which is Main winproc file i include ClassBB.h and
above the WinMain i declare

ClassBB clsB;

// i try this also
CurVar curvar;


So, 'clsB' and 'curvar' are global variable defined in Test.cpp, is that
correct?
And you want to access them from ClassAA::GetCurrentVariable() method,
defined in another .cpp file, right?

In that case, I would provide a couple of global accessors for these
variables, and declare them in a common header file, e.g.

 [File Common.h]

 // Forward declarations
 class ClassBB;
 class CurVar;

 // Function prototypes - Accessing global instances of ClassBB and
CurVar.
 ClassBB * GetClsB();
 CurVar * GetCurVar();

Then you can define these functions in Test.cpp, in the same file where
the variables 'clsB' and 'curvar' are defined:

[File Test.cpp]

// Define GetClsB() and GetCurVar() in the same file
// where clsB and curvar are defined

ClassBB clsB;
CurVar curvar;

ClassBB * GetClsB()
{
    return &clsB;
}

CurVar * GetCurVar()
{
  return &curvar;
}

In ClassAA::GetCurrentVariable() you can just call GetCurVar() and
GetClsB() to access these variables.

HTH,
Giovanni

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