FIX: Cannot Receive WM_HELP for a Subclassed Control

REFERENCES

• MFC source code for CWnd::OnHelpInfo().

    FixHelp(this);
				

Sample Code

/* Compile options needed:  Default
*/ 

//////////////////////////////////////////////////////////////////////// 
// FixHelp.h - Include this file in your dialog's or form view's .CPP

void FixHelp(CWnd* pWnd); // Call this from your OnInitDialog() for a
                          // dialog or OnInitialUpdate() for a CFormView

//////////////////////////////////////////////////////////////////////// 
// FixHelp.cpp - Insert this file into your project

#include "stdafx.h"

LRESULT CALLBACK ControlFixProc( HWND  hwnd, UINT  uMsg, WPARAM wParam,
                                                        LPARAM  lParam);

void FixHelp(CWnd* pWnd)
{
    // search all child windows.  If their window proc
    // is AfxWndProc, then subclass with our window proc
    CWnd* pWndChild = pWnd->GetWindow(GW_CHILD);
    while(pWndChild != NULL)
    {
        if (GetWindowLong(pWndChild->GetSafeHwnd(),
                                    GWL_WNDPROC) == (LONG)AfxWndProc)
        {
            SetWindowLong(pWndChild->GetSafeHwnd(), GWL_WNDPROC,
                                                (LONG)ControlFixProc);
        }
        pWndChild = pWndChild->GetWindow(GW_HWNDNEXT);
    }
}

LRESULT CALLBACK ControlFixProc(HWND  hwnd, UINT  uMsg, WPARAM wParam,
                                                        LPARAM  lParam)
{
    if (uMsg == WM_HELP)
    {
        // bypass MFC's handler, message will be sent to parent
        return DefWindowProc(hwnd, uMsg, wParam, lParam);
    }
    return AfxWndProc(hwnd,uMsg,wParam,lParam);
}

////////////////////////////////////////////////////////////////////////