C\C++笔记之小技巧

1. 以下是一个关于switch和define的用法

   #include <windows.h>
   #include <windowsx.h>
   #include "main.h"
   #include "dialogs.h"
   #include "resource.h"
   
   #ifndef _D_D_HAN
   #define _D_D_HAN
   #define HANDLE_MSG(hwnd,message,fn) case (message): return HANDLE_##message((hwnd),(wParam),(lParam),(fn)) 
   #endif
   
   BOOL WINAPI Main_Proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
   {
       switch(uMsg)
       {
           /* BEGIN MESSAGE CRACK */
           HANDLE_MSG(hWnd, WM_INITDIALOG, Main_OnInitDialog);
           HANDLE_MSG(hWnd, WM_COMMAND, Main_OnCommand);
           HANDLE_MSG(hWnd,WM_CLOSE, Main_OnClose);
           /* END MESSAGE CRACK */
       }
   
       return FALSE;
   }
   
   /*******************************************************************************
   *  Main_OnInitDialog
   */
   BOOL Main_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam)
   {
       /* Set app icons */
       HICON hIcon = LoadIcon((HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE) ,MAKEINTRESOURCE(IDI_ICONAPP));
       SendMessage(hwnd, WM_SETICON, TRUE,  (LPARAM)hIcon);
       SendMessage(hwnd, WM_SETICON, FALSE, (LPARAM)hIcon);
       
       /*
       * Add initializing code here
       */
       
       return TRUE;
   }
   
   /*******************************************************************************
   *  Main_OnCommand
   */
   void Main_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify)
   {
       switch(id)
       {
           case IDC_OK:
               MessageBox(hwnd,TEXT("You clicked OK!"),TEXT("dialog"),MB_OK);
               EndDialog(hwnd, id);
           break;
           case IDC_CANCEL:
               MessageBox(hwnd,TEXT("You clicked Cancel!"),TEXT("dialog"),MB_OK);
               EndDialog(hwnd, id);
           break;
           default:break;
       }
   
   }
   
   /*******************************************************************************
   *  Main_OnClose
   */
   void Main_OnClose(HWND hwnd)
   {
       EndDialog(hwnd, 0);
   }