您还可以在没有顶层菜单列的情况下使用菜单，也就是说，您可以使弹出式菜单出现在屏幕顶层的任何位置。一种方法是使用鼠标右键来启动弹出式菜单。程序10-6所示的POPMENU说明了这种方法。
程序10-6 POPMENU
POPMENU.C /*---------------------------------------------------------------------- POPMENU.C -- Popup Menu Demonstration (c) Charles Petzold, 1998 -------------------------------------------------------------------------*/ #include <windows.h> #include "resource.h" LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; HINSTANCE hInst ; TCHAR szAppName[] = TEXT ("PopMenu") ; int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { 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, szAppName) ; 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 ; } hInst = hInstance ; hwnd = CreateWindow ( szAppName, TEXT ("Popup 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 hMenu ; static int idColor [5] = {WHITE_BRUSH, LTGRAY_BRUSH, GRAY_BRUSH, DKGRAY_BRUSH, BLACK_BRUSH } ; static int iSelection = IDM_BKGND_WHITE ; POINT point ; switch (message) { case WM_CREATE: hMenu = LoadMenu (hInst, szAppName) ; hMenu = GetSubMenu (hMenu, 0) ; return 0 ; case WM_RBUTTONUP: point.x = LOWORD (lParam) ; point.y = HIWORD (lParam) ; ClientToScreen (hwnd, &point) ; TrackPopupMenu (hMenu, TPM_RIGHTBUTTON, point.x, point.y, 0, hwnd, NULL) ; return 0 ; case WM_COMMAND: switch (LOWORD (wParam)) { 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 ; case IDM_BKGND_WHITE: // Note: Logic below case IDM_BKGND_LTGRAY: // assumes that IDM_WHITE case IDM_BKGND_GRAY: // through IDM_BLACK are case IDM_BKGND_DKGRAY: // consecutive numbers in case IDM_BKGND_BLACK: // the order shown here. CheckMenuItem (hMenu, iSelection, MF_UNCHECKED) ; iSelection = LOWORD (wParam) ; CheckMenuItem (hMenu, iSelection, MF_CHECKED) ; SetClassLong (hwnd, GCL_HBRBACKGROUND, (LONG) GetStockObject (idColor [LOWORD (wParam) - IDM_BKGND_WHITE])) ; InvalidateRect (hwnd, NULL, TRUE) ; return 0 ; case IDM_APP_ABOUT: MessageBox (hwnd, TEXT ("Popup Menu Demonstration Program\n") TEXT ("(c) Charles Petzold, 1998"), szAppName, MB_ICONINFORMATION | MB_OK) ; return 0 ; case IDM_APP_EXIT: SendMessage (hwnd, WM_CLOSE, 0, 0) ; return 0 ; case IDM_APP_HELP: MessageBox (hwnd, TEXT ("Help not yet implemented!"), szAppName, MB_ICONEXCLAMATION | MB_OK) ; return 0 ; } break ; case WM_DESTROY: PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ; }