如何在非MFC程式中使用MFC類——解決#error : WINDOWS.H already included.

   我想在WinProc函數中使用CFileDialog類，於是#include <afxdlgs.h>以後編譯，出現了以下錯誤：

   c:/program files/microsoft visual studio/vc98/mfc/include/afxv_w32.h(14) : fatal error C1189: #error :  WINDOWS.H already included.  MFC apps must not #include <windows.h>

 

   於是， 我在VC6.0Integration Environment中的功能表項目project下的setting中設定使用MFC例"use mfc in a shared DLL"

   即：

       project->setting->general->Microsoft Foundation Classed: 選擇 Use MFC in a shared DLL"

 

   同時，加入：

   #include <afxwin.h>//使用MFC
   #include "afxdlgs.h"//使用CFileDialog類需要包含它

 

  #include "cv.h"
  #include "cxcore.h"
  #include "highgui.h"
  #include "stdafx.h"
  #include "resource.h"
  #include "commdlg.h"
  #include "direct.h"
  #include "stdio.h"
  #include "LbqSVM1.h"
  #include "HogOfImage.h"
  #include "Winbase.h"

 

  #include <afxwin.h>
  #include "afxdlgs.h"

 

  後編譯錯誤依然存在，於是把順序調換一下：

 

 #include <afxwin.h>
 #include "afxdlgs.h"

 #include "cv.h"
 #include "cxcore.h"
 #include "highgui.h"
 #include "stdafx.h"
 #include "resource.h"
 #include "commdlg.h"
 #include "direct.h"
 #include "stdio.h"
 #include "LbqSVM1.h"
 #include "HogOfImage.h"
 #include "Winbase.h"

 

 編譯通過！

 

 學會兩點：

 1、在project->setting->general->Microsoft Foundation Classed: 選擇 Use MFC in a shared DLL

 2、#include 順序調換可能會解決問題