windows程序设计 例题解析 NOPOPUPS.C

/*-------------------------------------------------
   NOPOPUPS.C -- Demonstrates No-Popup Nested Menu
                 (c) Charles Petzold, 1998
  -------------------------------------------------*/
#include 
#include "resource.h"
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{

 

        static TCHAR szAppName[] = TEXT ("NoPopUps") ;
         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  = NULL ;
         wndclass.lpszClassName = szAppName ;



    

     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
    
     hwnd = CreateWindow (szAppName,
                          TEXT ("No-Popup Nested 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 HMENU hMenuMain, hMenuEdit, hMenuFile ;
     HINSTANCE    hInstance ;
    
     switch (message)
     {
     case WM_CREATE:
          hInstance = (HINSTANCE) GetWindowLong (hwnd, GWL_HINSTANCE) ;
          
//加载了三个主菜单
          hMenuMain = LoadMenu (hInstance, TEXT ("MenuMain")) ;
          hMenuFile = LoadMenu (hInstance, TEXT ("MenuFile")) ;
          hMenuEdit = LoadMenu (hInstance, TEXT ("MenuEdit")) ;
  //把第一个主菜单显示出来       
          SetMenu (hwnd, hMenuMain) ;
          return 0 ;
         
     case WM_COMMAND:
          switch (LOWORD (wParam))
          {
          case IDM_MAIN:
               SetMenu (hwnd, hMenuMain) ; //切换到现在的MAIN主窗口
               return 0 ;
              
          case IDM_FILE:
               SetMenu (hwnd, hMenuFile) ; //切换到FILE主窗口
               return 0 ;
              
          case IDM_EDIT:
               SetMenu (hwnd, hMenuEdit) ; //切换到编辑主窗口
               return 0 ;
              
          case IDM_FILE_NEW:
          case IDM_FILE_OPEN:
          case IDM_FILE_SAVE:
          case IDM_FILE_SAVE_AS:
          case IDM_EDIT_UNDO:
          case IDM_EDIT_CUT:
          case IDM_EDIT_COPY:
          case IDM_EDIT_PASTE:
          case IDM_EDIT_CLEAR:
               MessageBeep (0) ;
               return 0 ;
          }
          break ;
         
     case WM_DESTROY:
          SetMenu (hwnd, hMenuMain) ;
          DestroyMenu (hMenuFile) ;
          DestroyMenu (hMenuEdit) ;
              
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}