#include for a class I created

Source code for MAIN program.  When I comment out the "#include "ObjectsDrawn.h" the program compiles just fine.



/*-----------------------------------------
   MENUDEMO.C -- Menu Demonstration
                 (c) Charles Petzold, 1998
  -----------------------------------------*/

#include <windows.h>
#include "resource.h"
#include "ObjectsDrawn.h"
#define ID_TIMER 1





LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

TCHAR szAppName[] = TEXT ("MenuDemo") ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     HWND     hwnd ;
     MSG      msg ;
     WNDCLASS wndclass ;
     
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = szAppName ;
     wndclass.lpszClassName = szAppName ;
     
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName, TEXT ("Menu Demonstration"),
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
     static int idColor [5] = { WHITE_BRUSH,  LTGRAY_BRUSH, GRAY_BRUSH,
                                DKGRAY_BRUSH, BLACK_BRUSH } ;
     static int iSelection = IDM_BKGND_WHITE ;
     HMENU      hMenu ;
     
     switch (message)
     {
     case WM_COMMAND:
          hMenu = GetMenu (hwnd) ;
         
          switch (LOWORD (wParam))
          {
          case IDM_CLEAR:
                     //MessageBox (hwnd, TEXT ("Clear function not yet implemented!"),
               //            szAppName, MB_ICONEXCLAMATION | MB_OK) ;
               return 0 ;
               
          case IDM_APP_EXIT:
               SendMessage (hwnd, WM_CLOSE, 0, 0) ;
               return 0 ;
               
          case IDM_EDIT_UNDO:
          case IDM_EDIT_CUT:
          case IDM_EDIT_COPY:
          case IDM_EDIT_PASTE:
          case IDM_EDIT_CLEAR:
               MessageBeep (0) ;
               return 0 ;
               
          case IDM_BKGND_WHITE:         // Note: Logic below
          case IDM_BKGND_LTGRAY:        //   assumes that IDM_WHITE
          case IDM_BKGND_GRAY:          //   through IDM_BLACK are
          case IDM_BKGND_DKGRAY:        //   consecutive numbers in
          case IDM_BKGND_BLACK:         //   the order shown here.
               
               CheckMenuItem (hMenu, iSelection, MF_UNCHECKED) ;
               iSelection = LOWORD (wParam) ;
               CheckMenuItem (hMenu, iSelection, MF_CHECKED) ;
               
               SetClassLong (hwnd, GCL_HBRBACKGROUND, (LONG)
                    GetStockObject
                             (idColor [LOWORD (wParam) - IDM_BKGND_WHITE])) ;
               
               InvalidateRect (hwnd, NULL, TRUE) ;
               return 0 ;
               
          case IDM_TIMER_START:
               if (SetTimer (hwnd, ID_TIMER, 1000, NULL))
               {
                    EnableMenuItem (hMenu, IDM_TIMER_START, MF_GRAYED) ;
                    EnableMenuItem (hMenu, IDM_TIMER_STOP,  MF_ENABLED) ;
               }
               return 0 ;
               
          case IDM_TIMER_STOP:
               KillTimer (hwnd, ID_TIMER) ;
               EnableMenuItem (hMenu, IDM_TIMER_START, MF_ENABLED) ;
               EnableMenuItem (hMenu, IDM_TIMER_STOP,  MF_GRAYED) ;
               return 0 ;
               
          case IDM_APP_HELP:
               MessageBox (hwnd, TEXT ("Help not yet implemented!"),
                           szAppName, MB_ICONEXCLAMATION | MB_OK) ;
               return 0 ;
               
          case IDM_APP_ABOUT:
               MessageBox (hwnd, TEXT ("Menu Demonstration Program\n")
                                 TEXT ("(c) Charles Petzold, 1998"),
                           szAppName, MB_ICONINFORMATION | MB_OK) ;
               return 0 ;
          }
          break ;
         
     case WM_TIMER:
          MessageBeep (0) ;
          return 0 ;
               
     case WM_DESTROY:
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}

H file for the OjbectsDrawn class

// ObjectsDrawn.h: interface for the ObjectsDrawn class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_OBJECTSDRAWN_H__204F6F06_EC28_11D3_B73C_9DAC4BE0123B__INCLUDED_)
#define AFX_OBJECTSDRAWN_H__204F6F06_EC28_11D3_B73C_9DAC4BE0123B__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class ObjectsDrawn  
{
private:
      int a;
public:
      ObjectsDrawn();
      virtual ~ObjectsDrawn();

};

#endif // !defined(AFX_OBJECTSDRAWN_H__204F6F06_EC28_11D3_B73C_9DAC4BE0123B__INCLUDED_)

CPP for the ObjectsDrawn class

// ObjectsDrawn.cpp: implementation of the ObjectsDrawn class.
//
//////////////////////////////////////////////////////////////////////

#include "ObjectsDrawn.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

ObjectsDrawn::ObjectsDrawn()
{

}

ObjectsDrawn::~ObjectsDrawn()
{

}

This did the trick!  Thank you so much!

Why doesn't VC just default the file extension to .cpp????  Wouldn't that be easier?  Then both C and C++ source code would be handled.

It's a cenvention files with the .c extension are treated as plain 'C' (by every C++ compiler)

BTW: VC defaults the extension to .cpp when saving a newly created file - but as you apparently took the sample 'as is', you ran into trouble... there's however a workaround when the problem is 'the other way round' - code can be guarded by using

#ifdef __cplusplus
// C++ specific code here
#endif

Oh, okay, cool!

Thanks again for the help and the info!

Tom