How to Disable the Move System Menu Item?

Question

In Microsoft Windows, this works:

 mnu := GetSystemMenu(h, false);
 EnableMenuItem(mnu, SC_CLOSE, MF_BYCOMMAND or MF_GRAYED);

But this does not work:

 mnu := GetSystemMenu(h, false);
 EnableMenuItem(mnu, SC_MOVE, MF_BYCOMMAND or MF_GRAYED);

Hence I know how to disable the "Close" system menu item of a window, but not the "Move" item. How do I do that?

Update

Of course one alternative to using the very nice function EnableMenuItem, is to use SetMenuItemInfo:

  FillChar(info, sizeOf(info), 0);
  with info do
  begin
    cbSize := sizeOf(info);
    fMask := MIIM_STATE;
    fState := MFS_GRAYED;
  end;
  SetMenuItemInfo(mnu, SC_MOVE, false, info);

But this again works perfectly for SC_CLOSE, but not at all for SC_MOVE!

Update 2

Even though the problem is resolved in the sense that a working code has been found that "does the job", so to speak, it would be interesting to hear hypotheses regarding the cause of the problem: Why does SC_CLOSE work but not SC_MOVE?

Answer 1

It's a bit of a mystery but it works if you use ModifyMenu or DeleteMenu:

   HMENU mnu = GetSystemMenu(hWnd, false);
   DeleteMenu(mnu, SC_MOVE, MF_BYCOMMAND);

or:

   HMENU mnu = GetSystemMenu(hWnd, false);
   MENUITEMINFO info = { sizeof(MENUITEMINFO) };
   TCHAR name[256] = _T("Cannot move");
   info.fMask = MIIM_TYPE;
   info.dwTypeData = name;
   info.cch = sizeof(name) / sizeof(TCHAR);
   GetMenuItemInfo(mnu, SC_MOVE, false, &info);
   ModifyMenu(mnu, SC_MOVE, MF_BYCOMMAND | MF_GRAYED, 0, info.dwTypeData);