MF_POPUP に MF_POPUP を追加してサブメニューを作ることができます。
#include <windows.h>
#define CURRY 1
#define HAMBURG 2
#define COFFEE 3
#define JUICE 4
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
void AddMenu (HWND);
int PASCAL WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
WNDCLASS wc;
HWND hwnd;
MSG msg;
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = NULL;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = "SUBMENU";
RegisterClass(&wc);
hwnd = CreateWindow("SUBMENU",
"SubMenu",
WS_OVERLAPPEDWINDOW | WS_VISIBLE,
CW_USEDEFAULT, CW_USEDEFAULT, 300, 200,
NULL, NULL, hInstance, NULL);
while (GetMessage(&msg, NULL, 0, 0))
{
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
static HWND label;
RECT rect;
switch (msg)
{
case WM_CREATE:
AddMenu(hwnd);
GetClientRect(hwnd, &rect);
label = CreateWindow("STATIC",
"",
WS_CHILD | WS_VISIBLE | SS_CENTER,
(rect.right - 60) / 2,
(rect.bottom - 20) / 2,
60, 20, hwnd, NULL, NULL, NULL);
return 0;
case WM_SIZE:
GetClientRect(hwnd, &rect);
SetWindowPos (label, HWND_TOP,
(rect.right - 60) / 2,
(rect.bottom - 20) / 2,
0, 0, SWP_NOSIZE);
return 0;
case WM_COMMAND:
switch (wParam)
{
case CURRY:
SendMessage(label, WM_SETTEXT, 0, (LPARAM)"Curry");
break;
case HAMBURG:
SendMessage(label, WM_SETTEXT, 0, (LPARAM)"Hamburg");
break;
case COFFEE:
SendMessage(label, WM_SETTEXT, 0, (LPARAM)"Coffee");
break;
case JUICE:
SendMessage(label, WM_SETTEXT, 0, (LPARAM)"Juice");
break;
}
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
void AddMenu(HWND hwnd)
{
HMENU menubar = CreateMenu();
HMENU menumenu = CreateMenu();
HMENU menufood = CreateMenu();
HMENU menudrink = CreateMenu();
AppendMenu(menumenu, MF_POPUP, (UINT)menufood, "Food");
AppendMenu(menumenu, MF_POPUP, (UINT)menudrink, "Drink");
AppendMenu(menubar, MF_POPUP, (UINT)menumenu, "Menu");
AppendMenu(menufood, MF_STRING, CURRY, "Curry");
AppendMenu(menufood, MF_STRING, HAMBURG, "Hamburg");
AppendMenu(menudrink, MF_STRING, COFFEE, "Coffee");
AppendMenu(menudrink, MF_STRING, JUICE, "Juice");
SetMenu (hwnd, menubar);
}