编写简单的windows桌面计算器程序

编译环境：VS2017

主文件为：

 #include "stdafx.h"
 #include "WindowsProject5.h"
 #include "Resource.h"
 #define NULL 0

 //回调函数
 BOOL CALLBACK    MainProc(
     HWND hwndDlg,
     UINT uMsg,
     WPARAM wParam,
     LPARAM lParam)
 {
     //以下三行为调试语句，可去除
     char s[];
     wsprintf((LPWSTR)s,L"uMsg=%d,wParam=%d,lParam=%d\n", uMsg, wParam, (int)lParam);
     OutputDebugStringW((LPWSTR)s);

     //对于菜单、加速键来说，点击后发送WM_COMMAND消息
     if (WM_COMMAND == uMsg)
     {
         //如果点击取消按钮，关闭对话框
         if (LOWORD(wParam) == IDCANCEL)
         {
             EndDialog(hwndDlg, IDCANCEL);
             return TRUE;
         };
         //如果点击计算按钮，进行加法计算，得出结果
         if (LOWORD(wParam) == IDOK)
         {
             int nLeft = GetDlgItemInt(hwndDlg, IDC_LEFT, NULL, TRUE);
             int nRight = GetDlgItemInt(hwndDlg, IDC_RIGHT, NULL, TRUE);
             int nResult = nLeft + nRight;
             SetDlgItemInt(hwndDlg,IDC_RESULT,nResult,TRUE);
         }
     }
     return FALSE;
 }

 //win主函数
 int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                      _In_opt_ HINSTANCE hPrevInstance,
                      _In_ LPWSTR    lpCmdLine,
                      _In_ int       nCmdShow)
 {

     DialogBox(hInstance,(LPWSTR)IDD_DIALOG1,,(DLGPROC)MainProc);
     return ;
  }

资源文件：

 #define IDI_ICON2                       131
 #define IDD_DIALOG1                     133
 #define IDC_RESULT                      1004
 #define IDC_RIGHT                       1005
 #define IDC_LEFT                        1006
 #define IDC_STATIC                      -1

对话框截图：

运行结果：