Global Variables

Your typedefs and enums should go in a header file included in the .cpp files.

ex :
#include "typedefs.h"

Global variables should go in a .cpp file and be externed in a header file that''s included.

ex:
extern int iVar;

Form1.cpp is used to handle the control for a MFC form. You''ll handle all the button presses and whatever else is on your MFC app from there.

I wrote this in the GlobalDef.cpp file:


#include "stdafx.h"
#include "GlobalDef.h"

extern int iVar;


and in the GlobalDef.h file, I didn't wrote anything

I included the GlobalDef.h file in the Form1.h file and I cant use the iVar variable int the Form1.h file

what should I do?

and also if I try to Declare a String object I get an error:

d:\Tzipi Project\Printing 1.01\Printing 1.01\GlobalDef.h(4): error C3145: 'tempFrm' : cannot declare a global or static managed type object or a __gc pointer

What should I do about this either?



[edited by - DorRaba on May 5, 2004 10:14:24 AM]

Please Help me, its urgent...

Hi,

listing ...

globals.h

extern int X;
extern int Y;

globals.cpp

#include "globals.h"

int X;
int Y;

somefile.cpp

#include "globals.h"

void someFunction(int w, int p) {
    X = w;  // ok because they are externs

    Y = p;

}

globals.cpp :

int foo_dot_bar;

globals.h :

#ifndef GLOBALS_HH
#define GLOBALS_HH

extern int foo_dot_bar;

#endif

Everywhere you wanna use foo_dot_bar, you include globals.h


[edited by - George2 on May 5, 2004 10:46:15 AM]

Hi George2,

I agree, the extern keyword means that the variable is defined externally. One question :

How does the compiler know to use the globals.cpp file?

Do you just add it to the project or is it linked with include statements?

[edited by - ray_intellect on May 5, 2004 10:51:56 AM]

Thanks, it works just fine with variables like int, bool and all of that, but when I try to to this for String* of a Form* object, I get this error message:

d:\Tzipi Project\Printing 1.01\Printing 1.01\GlobalDef.h(4): error C3145: ''tempFrm'' : cannot declare a global or static managed type object or a __gc pointer

so what can I do with that?
don''t forget that I''m using a visual c++ .NET environemnt.

ray_intellect, the global.cpp has to be part of the project in order to be compiled (it won''t be linked by includes).

the compiler doesn''t care about where the variable declared with extern is ... that''s something the linker cares about.


Indeterminatus

--si tacuisses, philosophus mansisses--

Can anyone answer my question above?

Please help me with the question above, its urgent...

Isn''t there a way to pass this, and declare global __gc class object?