非常怪的问题(关于MDI)

{-----------------------------------------------------------------
Paste followd code into your old forms.pas file to fix the bug:
When maximizes several child windows in MDI,and closes the top one,then the window menus of next child don't disappear or become grey.
By Gene Fowler - acorioso@ccnet.com
-----------------------------------------------------------------}
procedure TCustomForm.MergeMenu(MergeState: Boolean);  
 var  
   AMergeMenu: TMainMenu;  
   Size: Longint;  
   FixMaximize: boolean;  
 begin  
   if not (fsModal in FFormState) and  
     (Application.MainForm <> nil) and  
     (Application.MainForm.Menu <> nil) and  
     (Application.MainForm <> Self) and  
     ((FormStyle = fsMDIChild) or (Application.MainForm.FormStyle <>
 fsMDIForm)) then  
   begin  
     AMergeMenu := nil;  
     if not (csDesigning in ComponentState) and (Menu <> nil) and  
       (Menu.AutoMerge or (FormStyle = fsMDIChild)) then AMergeMenu := Menu;  
     FixMaximize := MergeState and (FormStyle = fsMDIChild) and  
     (WindowState = wsMaximized);  
     // The important change from the healthy MergeMenu from D4  
     // is that the Restore/RE-maximize are split up to match the  
     // behavior described in the Win32 Help's wm_MDINext topic (at  
     // the bottom).  
     if FixMaximize then begin  
       { Force MDI to put back the system menu of a maximized child }  
       Size := ClientWidth + (Longint(ClientHeight) shl 16);  
       SendMessage(Handle, WM_SIZE, SIZE_RESTORED, Size);  
     end;  
     try  
     with Application.MainForm.Menu do  
     if MergeState then Merge(AMergeMenu) else Unmerge(AMergeMenu);  
     finally  
     if FixMaximize then  
       begin  
         Size := ClientWidth + (Longint(ClientHeight) shl 16);  
         SendMessage(Handle, WM_SIZE, SIZE_MAXIMIZED, Size);  
       end;  
     end;  
   end;  
 end;