c++ - Window creation fails with non-NULL hMenu parameter -
in addition main window, i'm trying create top level window. problem when i'm setting second window's hmenu parameter non-null value, doesn't show up.
e.g:
this window shows (hmenu == 0)
case idc_button_send_command: { createwindowexw(null, l"commandwindow", l"send command", ws_visible | ws_overlapped | ws_caption | ws_sysmenu | ws_minimizebox, 100, 100, 600, 400, null, (hmenu)0, (hinstance)getwindowlong(hwnd, gwl_hinstance), null); break; } this window doesn't show (hmenu == 4)
case idc_button_send_command: { createwindowexw(null, l"commandwindow", l"send command", ws_visible | ws_overlapped | ws_caption | ws_sysmenu | ws_minimizebox, 100, 100, 600, 400, null, (hmenu)4, (hinstance)getwindowlong(hwnd, gwl_hinstance), null); break; } i'm using windows 7.
passing (hmenu)4 hmenu parameter createwindowex create top level window tells system attach menu it. menu has menu handle 4. menu handle (hmenu) returned functions createmenu. if handle not valid hmenu window creation fails.
your observation, window doesn't show up misleading believing window exists. window doesn't exist, , createwindowex returns null. checking return values advisable, , calling getlasterror when api call fails quite helpful.
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