windows程序设计 例题解析 NOPOPUPS.C

/*-------------------------------------------------   NOPOPUPS.C -- Demonstrates No-Popup Nested Menu                 (c) Charles Petzold, 1998  -------------------------------------------------*/#include <windows.h>#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) ;}