How To Trapping Server's Menu Commands in Composite Menu Bar

MORE INFORMATION

When the server is in-place activated, the COleClientItem::OnInsertMenus() function will be called to install the composite menu. When the server is deactivated, the COleClientItem::OnRemoveMenus() function will be called to remove the composite menu. We can make use of these two functions to determine the menu selection when the composite menu is shown.

In the following sample code, Microsoft Word is the server application in an AppWizard-generated MFC container application. The steps to trap the Word's Edit/Paste menu command follow:

1. Add a public member variable named m_hSharedMenu of type HMENU to the container's CWinApp-derived class. Initialize its value to NULL in the constructor function. It is public because it will be accessed by functions in the COleClientItem-derived class.
2. Override both the OnInsertMenus() and OnRemoveMenus() functions of the COleClientItem-derived class. Set the value of the m_hSharedMenu variable to the HMENU of the composite menu in the OnInsertMenus() function, and assign NULL to m_hSharedMenu in the OnRemoveMenus() function.
   

      // CContainerCntrItem is a COleClientItem-derived class.
      void CContainerCntrItem:OnInsertMenus(
          CMenu* pMenuShared, LPOLEMENUGROUPWIDTHS lpMenuWidths)
      {
          ((CContainerApp *) AfxGetApp())->m_hSharedMenu =
              pMenuShared->GetSafeHmenu();
          COleClientItem::OnInsertMenus(pMenuShared, lpMenuWidths);
      }
   
      void CContainerCntrItem::OnRemoveMenus(CMenu* pMenuShared)
      {
          ((CContainerApp *) AfxGetApp())->m_hSharedMenu = NULL;
          COleClientItem::OnRemoveMenus(pMenuShared);
      }
   						

3. Override PreTranslateMessage() of the CWinApp-derived class to trap the selection of the Edit/Paste menu command.
   

      // CContainerApp is a CWinApp-derived class.
      BOOL CContainerApp::PreTranslateMessage(MSG* pMsg)
      {
          if (pMsg->message == WM_COMMAND && m_hSharedMenu)
          {
           // The drop-down menu in the menu bar is 0-based. To simplify the
           // code, we make an assumption that the Edit menu is at position
           // one, instead of looping through the main menu to find out the
           // position of the Edit menu.
           char str[80];
           ::GetMenuString(m_hSharedMenu, 1, str, sizeof(str),
               MF_BYPOSITION);
           TRACE("submenu = %s\n", str);
   
           HMENU hsub = ::GetSubMenu(m_hSharedMenu, 1);
   
           // Get the menu string of the selected menu item.
           ::GetMenuString(hsub, pMsg->wParam, str, sizeof(str),
               MF_BYCOMMAND);
           TRACE("menu item = %s\n", str);
   
           // Do something when Edit\Paste menu command is selected.
           if (lstrcmp(str, "&Paste\tCtrl+V") == 0)
               TRACE("Word's Edit\\Paste menu command is selected\n");
           return TRUE;
       }
       else
           return CWinApp::PreTranslateMessage(pMsg);
      }
   						

I, Yeong-Kah Tam, give Microsoft Corporation permission to publish my name as a contributor to this article.