Multiple Selection Menu – Part 2

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The previous article showed how tu use a WH_MSGFILTER hook in order to make a menu with multiple selection. Now, let’s see an MFC-extension class that implements a context pop-up menu with multiple selection.

CMultiSelPopupMenu class

class CMultiSelPopupMenu : public CMenu
{
// Construction
public:
   CMultiSelPopupMenu(UINT nIDResource, UINT nSubMenu);

// Operations
public:
   void MDX_Check(CDataExchange* pDX, WORD wItemID, BOOL& bCheck);
   BOOL Show(UINT nFlags, CPoint point, CWnd* pWnd);

// ... 
};

CMultiSelPopupMenu class is derived from CMenu MFC class and has three public methods:

  1. CMultiSelPopupMenu::CMultiSelPopupMenu constructs a CMultiSelPopupMenu object.
    Parameters:

    • nIDResource – resource identifier of the menu;
    • nSubMenu – the index of pop-up sub-menu to be shown.
  2. CMultiSelPopupMenu::MDX_Check looks very similar to DDX_Check global function from the MFC framework. While DDX_Check is used to manage data exchange between check box controls and window class objects, CMultiSelPopupMenu::MDX_Check manages data exchange between multiple-selection menus and window class objects.
    Parameters:

    • pDX – a pointer to a CDataExchange object; it has the same purpose as in DDX_Check;
    • wItemID – the identifier of the menu item;
    • bCheck – a reference to a member variable of the window class object with which data is exchanged.
  3. CMultiSelPopupMenu::Show shows a pop-up context menu. It is similar to CMenu::TrackPopupMenu, except that shown menu allows multipe selection.
    Parameters:

    • nFlags – specifies screen-position and mouse-position flags; see TrackPopupMenu documentation for more details;
    • point – screen coordinates of the pop-up menu;
    • pWnd – the window that owns the pop-up menu.

You can get more usage and implementation details from the attached demo project. I think, the source code can tell more than any other explanations. However, if something isn’t very clear, please do not hesitate to leave a reply.

Demo project

The demo project is a simple MFC application that shows a multiple-selection context menu when the user right-clicks in the client area of the window. Click on items to check/uncheck the desired ones. Finally, to dismiss the menu just click outside.

Multiple-selection context menu
Multiple-selection context menu

See also

Downloads

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